Tagged: Science Alert (AU) Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 7:18 am on May 10, 2021 Permalink | Reply
    Tags: "New marine symbiosis unseen for 270 million years", , , , Science Alert (AU),   

    From University of Warsaw [Uniwersytet Warszawski] (PL) and Science Alert (AU) : “New marine symbiosis unseen for 270 million years” 

    From University of Warsaw [Uniwersytet Warszawski] (PL)

    and

    ScienceAlert

    Science Alert (AU)

    30 April 2021

    A symbiotic relationship between two marine lifeforms has just been discovered thriving at the bottom of the ocean, after disappearing from the fossil record for hundreds of millions of years.

    Scientists have found non-skeletal corals growing from the stalks of marine animals known as crinoids, or sea lilies, on the floor of the Pacific Ocean, off the coasts of Honshu and Shikoku in Japan.

    “These specimens represent the first detailed records and examinations of a recent syn vivo association of a crinoid (host) and a hexacoral (epibiont),” the researchers wrote in their paper, “and therefore analyses of these associations can shed new light on our understanding of these common Paleozoic associations.”

    During the Paleozoic era, crinoids and corals seem to have gotten along very well indeed. The seafloor fossil record is full of it, yielding countless examples of corals overgrowing crinoid stems to climb above the seafloor into the water column, to stronger ocean currents for filter-feeding.

    Prof. Mikołaj Zapalski from the UW Faculty of Geology with researchers from Japan and Poland described an ecological “living fossil” unseen for 273 million years. Their article appeared in Palaeogeography, Palaeoclimatology, Palaeoecology.

    1
    Credit: Zapalski et al., Palaeogeography, Palaeoclimatology, Palaeoecology, 2021.

    2
    Credit: Zapalski et al., Palaeogeography, Palaeoclimatology, Palaeoecology, 2021.

    Palaeozoic seafloors were inhabited by numerous organisms interacting with each other. One of these associations was corals growing on sea lilies (crinoids). As corals grew on crinoids, they were lifted above the seafloor, thus profiting from stronger feeding currents. Fossils of crinoid-coral associations are known from Palaeozoic rocks, and the youngest are known from rocks dated from ca. 273 million years ago. While both corals and crinoids are known from younger rocks, such associations are unknown neither from Meso- and Cenozoic strata nor contemporary seas.

    In a research article [above], Prof. Mikołaj Zapalski from the UW Faculty of Geology with collaborators from Japan and Poland described an ecological “living fossil” unseen for 273 million years; non-skeletal corals growing on crinoid stalks. The investigated animals were collected from depths exceeding 100 m near the Pacific coasts of Honshu and Shikoku. The research was conducted using microtomography scanning and revealed that, unlike their Palaeozoic counterparts, recent corals do not modify the host’s skeleton. Despite such differences in the skeletal record, the newly discovered coral-crinoid associations may serve as a good model of relevant Palaeozoic interactions.

    See the full University of Warsaw [Uniwersytet Warszawski] (PL)article here.

    10 MAY 2021
    MICHELLE STARR

    A symbiotic relationship between two marine lifeforms has just been discovered thriving at the bottom of the ocean, after disappearing from the fossil record for hundreds of millions of years.

    Scientists have found non-skeletal corals growing from the stalks of marine animals known as crinoids, or sea lilies, on the floor of the Pacific Ocean, off the coasts of Honshu and Shikoku in Japan.

    “These specimens represent the first detailed records and examinations of a recent syn vivo association of a crinoid (host) and a hexacoral (epibiont),” the researchers wrote in their paper, “and therefore analyses of these associations can shed new light on our understanding of these common Paleozoic associations.”

    During the Paleozoic era, crinoids and corals seem to have gotten along very well indeed. The seafloor fossil record is full of it, yielding countless examples of corals overgrowing crinoid stems to climb above the seafloor into the water column, to stronger ocean currents for filter-feeding.

    Yet these benthic besties disappeared from the fossil record around 273 million years ago, after the specific crinoids and corals in question went extinct. Other species of crinoids and corals emerged in the Mesozoic, following the Permian-Triassic extinction – but never again have we seen them together in a symbiotic relationship.

    Well, until now. At depths exceeding 100 meters (330 feet) below the ocean’s surface, scientists have found two different species of coral – hexacorals of the genera Abyssoanthus, which is very rare, and Metridioidea, a type of sea anemone – growing from the stems of living Japanese sea lilies (Metacrinus rotundus).

    The joint Polish-Japanese research team, led by paleontologist Mikołaj Zapalski of the University of Warsaw in Poland, first used stereoscopic microscopy to observe and photograph the specimens.

    Then, they used non-destructive microtomography to scan the specimens to reveal their interior structures, and DNA barcoding to identify the species.

    They found that the corals, which attached below the feeding fans of the crinoids, likely didn’t compete with their hosts for food; and, being non-skeletal, likely didn’t affect the flexibility of the crinoid stalks, although the anemone may have hindered movement of the host’s cirri – thin strands that line the stalk.

    It’s also unclear what benefit the crinoids gain from a relationship with coral, but one interesting thing did emerge: unlike the Paleozoic corals, the new specimens did not modify the structure of the crinoids’ skeleton.

    This, the researchers said, can help explain the gap in the fossil record. The Paleozoic fossils of symbiotic corals and crinoids involve corals that have a calcite skeleton, such as Rugosa and Tabulata.

    Fossils of soft-bodied organisms – such as non-skeletal corals – are rare. Zoantharia such as Abyssoanthus have no confirmed fossil record, and actiniaria such as Metridioidea (seen as a dry specimen in the image below) also are extremely limited.

    4
    (Zapalski et al., Palaeogeography, Palaeoclimatology, Palaeoecology, 2021)

    If these corals don’t modify the host, and leave no fossil record, perhaps they have had a long relationship with crinoids that has simply not been recorded.

    This means the modern relationship between coral and crinoid could contain some clues as to Paleozoic interactions between coral and crinoid. There’s evidence to suggest that zoantharians and rugose corals share a common ancestor, for instance.

    The number of specimens recovered to date is small, but now that we know they are there, perhaps more work can be done to discover the history of this fascinating friendship.

    “As both Actiniaria and Zoantharia have their phylogenetic roots deep in the Palaeozoic, and coral-crinoid associations were common among Palaeozoic Tabulate and Rugose corals, we can speculate that also Palaeozoic non-skeletal corals might have developed this strategy of settling on crinoids,” the researchers wrote in their paper.

    “The coral-crinoid associations, characteristic of Palaeozoic benthic communities, disappeared by the end of Permian, and this current work represents the first detailed examination of their rediscovery in modern seas.”

    See the full Science Alert (AU) article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Warsaw [Uniwersytet Warszawski] (PL), established in 1816, is the largest university in Poland. It employs over 6,000 staff including over 3,100 academic educators. It provides graduate courses for 53,000 students (on top of over 9,200 postgraduate and doctoral candidates). The University offers some 37 different fields of study, 18 faculties and over 100 specializations in Humanities, technical as well as Natural Sciences.

    It was founded as a Royal University on 19 November 1816, when the Partitions of Poland separated Warsaw from the oldest and most influential University of Kraków. Alexander I granted permission for the establishment of five faculties – law and political science, medicine, philosophy, theology and the humanities. The university expanded rapidly but was closed during November Uprising in 1830. It was reopened in 1857 as the Warsaw Academy of Medicine, which was now based in the nearby Staszic Palace with only medical and pharmaceutical faculties. All Polish-language campuses were closed in 1869 after the failed January Uprising, but the university managed to train 3,000 students, many of whom were important part of the Polish intelligentsia; meanwhile the Main Building was reopened for training military personnel. The university was resurrected during the First World War and the number of students reached 4,500 in 1918. After Poland’s independence the new government focused on improving the university, and in the early 1930s it became the country’s largest. New faculties were established and the curriculum was extended. Following the Second World War and the devastation of Warsaw, the University successfully reopened in 1945.

    Today, University of Warsaw [Uniwersytet Warszawski] (PL) consists of 126 buildings and educational complexes with over 18 faculties: biology, chemistry, journalism and political science, philosophy and sociology, physics, geography and regional studies, geology, history, applied linguistics and Slavic philology, economics, philology, pedagogy, Polish language, law and public administration, psychology, applied social sciences, management and mathematics, computer science and mechanics.

    The University of Warsaw [Uniwersytet Warszawski] (PL) is one of the top Polish universities. It was ranked by Perspektywy magazine as best Polish university in 2010, 2011, 2014 and 2016. International rankings such as ARWU and University Web Ranking rank the university as the best Polish higher level institution. On the list of 100 best European universities compiled by University Web Ranking, the University of Warsaw [Uniwersytet Warszawski] (PL) was placed as 61st. QS World University Rankings previously positioned the University of Warsaw [Uniwersytet Warszawski] (PL) as the best higher level institution among the world’s top 400.

     
  • richardmitnick 9:58 am on May 8, 2021 Permalink | Reply
    Tags: "Powerful Magnetic Fields in Space Have Been Seen Bending Black Hole Jets", A galaxy called MRC 0600-399, A galaxy cluster called Abell 3376, Joint Space-Science Institute UMD (US) and GSFC (US), Science Alert (AU)   

    From Joint Space-Science Institute UMD (US) and GSFC (US) via Science Alert (AU) : “Powerful Magnetic Fields in Space Have Been Seen Bending Black Hole Jets” 

    1

    From Joint Space-Science Institute UMD (US) and GSFC (US)

    via

    ScienceAlert

    Science Alert (AU)

    7 MAY 2021
    MICHELLE STARR

    1
    (Chibueze, Sakemi, Ohmura et al.; Takumi Ohmura, Mami Machida, Hirotaka Nakayama, 4D2U Project, National Astronomical Observatory of Japan [国立天文台](JP))
    The bent jet structures as observed by MeerKAT (left). On the right are simulations showing how magnetic fields could be causing these shapes.

    In a galaxy cluster called Abell 3376, some 600 million light-years from Earth, one galaxy has an active supermassive black hole, gobbling up matter at a furious rate – a process that blasts powerful jets of plasma hundreds of thousands, sometimes even millions, of light-years into intergalactic space.

    Astronomers have now found that, at a certain distance from the black hole, these jets are being bent at a right angle by powerful intergalactic magnetic fields.

    That galaxy is called MRC 0600-399, and its jets were already known for their bizarre, bent shape.

    But this new research supports the idea that this is the result of complex magnetic fields generated by interactions between galaxies in the cluster and the intergalactic medium.

    Intracluster magnetic fields can reveal a lot about galaxy clusters, such as how they grow, and the impact they have on the clusters themselves. However, these magnetic fields are difficult to observe directly.

    This new discovery suggests a way we can now study them.

    When something interacts with a magnetic field, it’s possible to make out details – and, as it turns out, black hole jets can delineate magnetic fields beautifully.

    Black hole jets are fascinating structures. Nothing that we can currently detect can escape a black hole once it’s passed the critical proximity threshold, but not all the material in the accretion disk swirling of material into an active black hole inevitably ends up beyond the event horizon.

    A small fraction of it somehow gets funneled from the inner region of the accretion disk to the poles, where it is blasted into space in the form of jets of ionized plasma, at speeds a significant percentage of the speed of light.

    Astronomers think that the black hole’s magnetic field plays a role in this process. The magnetic field lines, according to this model, act as a synchrotron that accelerates material before launching it at tremendous speed. From there, these highly collimated jets, thought to be shaped by magnetic fields, can extend vast distances into intergalactic space.

    They’re detectable in radio wavelengths, and we’ve found a fair few of them. But the shape of the jets from MRC 0600-399 is really unusual, so an international team of scientists decided to take a closer look, using the powerful Meerkat radio telescope in South Africa.

    Equipped with the new observations, much higher resolution than previously obtained, the researchers were able to study the jets in unprecedented detail.

    The images showed that the jets bend at almost 90-degree angles, as had been previously observed [Science]. Strikingly, though, the images also show diffuse regions of radio emission at both sides of the point at which the jet bends, creating a T-shape, which the researchers refer to as ‘double-scythe’.

    Next, the team ran simulations to try to reproduce the shape of the jet. They showed that a black hole jet traveling at supersonic speeds colliding with a curved layer of magnetic field that it couldn’t penetrate could reproduce the observed shape of MRC 0600-399’s jets.

    Much like a stream of water striking a hard surface, this collision would be chaotic and messy.

    It’s not the only explanation [Nature]. Another is that MRC 0600-399 may be currently falling back towards the center of Abell 3376, after being kicked out at supersonic speed.

    The bending of the jets could have been caused by ram pressure from the surrounding intergalactic gas. Even if this is the case, though, it can’t explain all of the features of the bent jets, including the double-scythe structures, so the presence of a magnetic field is likely still necessary.

    It’s an exciting finding because it demonstrates the presence of strong, well-ordered magnetic fields inside galaxy clusters, environments that are often complicated and unkempt. This could help better understand galaxy cluster dynamics.

    It also shows that black hole jets can be used as an excellent tool for understanding mysterious, hard-to-see magnetic fields in deep space.

    And perhaps not least, the research may even be able to help astronomers better understand how magnetic fields can shape and guide the powerful plasma jets blasting out of active supermassive black holes.

    The research has been published in Nature.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.


    Stem Education Coalition

     
  • richardmitnick 8:46 am on May 5, 2021 Permalink | Reply
    Tags: "The Mystery of White Dwarfs With Intense Magnetic Fields Could Finally Be Solved", , , , , Science Alert (AU),   

    From University of Warwick (UK) via Science Alert (AU) : “The Mystery of White Dwarfs With Intense Magnetic Fields Could Finally Be Solved” 

    From University of Warwick (UK)

    via

    ScienceAlert

    Science Alert (AU)

    4 MAY 2021
    MICHELLE STARR

    1
    White dwarf at the heart of the Helix nebula. Credit: K. Su National Aeronautics Space Agency (US)/Chandra X-ray Center (US)/NASA JPL-Caltech (US)/Caltech Spitzer Science Center (US)/NASA Space Telescope Science Institute (US)/European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/National Radio Astronomy Observatory (US)

    There’s a lot we don’t understand about white dwarf stars, but one mystery may finally have a solution: how do some of these cosmic objects end up having insanely powerful magnetic fields?

    According to new calculations and modelling, these super-dense objects can have a magnetosphere-generating dynamo – but the strongest white dwarf magnetic fields, a million times more powerful than Earth’s, only occur within certain contexts.

    Not only does the research resolve several long-standing problems, but once again it shows that very similar phenomena can be observed in wildly different astronomical objects, and that sometimes the Universe is more like itself than we might initially think.

    White dwarf stars are what we colloquially call “dead” stars. When a star less than around eight times the mass of the Sun reaches the end of its lifespan, having run out of elements suitable for nuclear fusion, it ejects its outer material. The remaining core collapses down into an object less than 1.4 times the mass of the Sun, packed into a sphere around the size of Earth.

    The resulting object, shining brightly with residual thermal energy, is a white dwarf, and it’s incredibly dense. Just a single teaspoon of white dwarf material would weigh around 15 tons, which means it would not be unreasonable to assume that the interiors of these objects would be very different from the interiors of planets like Earth.

    Astrophysicists have been trying to work out how white dwarf stars can have powerful magnetic fields, in ranges up to around a million times stronger than Earth’s. For context, the Sun’s magnetic field is twice as powerful as Earth’s – so something unusual has to be going on with white dwarfs.

    It gets a little tricky, though. Only some white dwarfs have powerful magnetic fields. White dwarfs in detached binaries – in which neither star exceeds the region of space within which stellar material is bound by gravity, known as a Roche lobe – less than a billion years old don’t have these magnetic fields.

    But for white dwarfs in semi-detached binaries, where one of the stars spills out of its Roche lobe, and the white dwarf is gravitationally slurping material off its lower-mass companion, more than a third of these exhibit strong magnetic fields. And a few strongly magnetic white dwarfs appear in older detached binaries, too.

    Stellar evolution models have been unable to explain how this happens, so an international team of astrophysicists took a different approach, proposing a core dynamo that develops over time, rather than at the time of the white dwarf’s formation.

    That dynamo would be a rotating, convecting, and electrically conducting fluid that converts kinetic energy into magnetic energy, spinning a magnetic field out into space. In Earth’s case, convection is generated by liquid iron moving around the core.

    “We have known for a long time that there was something missing in our understanding of magnetic fields in white dwarfs, as the statistics derived from the observations simply did not make sense,” said physicist Boris Gänsicke of the University of Warwick (UK) .

    “The idea that, at least in some of these stars, the field is generated by a dynamo can solve this paradox.”

    When a white dwarf first forms, right after losing its outer envelope, it’s very hot, made up of fluid carbon and oxygen. According to the team’s model, as the core of the white dwarf cools and crystallizes, heat escaping outwards creates convection currents, very similar to the way fluid moves around inside Earth, producing a dynamo.

    “As the velocities in the liquid can become much higher in white dwarfs than on Earth, the generated fields are potentially much stronger,” explained physicist Matthias Schreiber of the Federico Santa María Technical University [Universidad Técnica Federico Santa María] (CL).

    “This dynamo mechanism can explain the occurrence rates of strongly magnetic white dwarfs in many different contexts, and especially those of white dwarfs in binary stars.”

    As the white dwarf cools and ages, its orbit with its binary companion grows closer. When the companion exceeds its Roche lobe, and the white dwarf begins accreting material, the spin rate of the white dwarf increases; this faster rotation also affects the dynamo, producing an even stronger magnetic field.

    If this magnetic field is strong enough to connect with the magnetic field of the binary companion, the binary companion exerts a torque that causes its orbital motion to synchronize with the white dwarf’s spin, which in turn causes the binary companion to detach from its Roche lobe, returning the system to a detached binary. This process will eventually repeat.

    A different mechanism will probably be required to explain the very strongest white dwarf magnetic field strengths, but for now, the team’s results are consistent with observations. White dwarfs in detached binaries are older than a billion years, and have previously experienced mass transfer in a semi-detached stage cut short when a wild magnetic field appeared.

    If the team’s model is accurate, future white dwarf observations will continue to be consistent with their findings.

    “The beauty of our idea is that the mechanism of magnetic field generation is the same as in planets,” Schreiber said.

    “This research explains how magnetic fields are generated in white dwarfs and why these magnetic fields are much stronger than those on Earth. I think it is a good example of how an interdisciplinary team can solve problems that specialists in only one area would have had difficulty with.”

    The research has been published in Nature Astronomy.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The establishment of the The University of Warwick (UK) was given approval by the government in 1961 and received its Royal Charter of Incorporation in 1965.

    The idea for a university in Coventry was mooted shortly after the conclusion of the Second World War but it was a bold and imaginative partnership of the City and the County which brought the University into being on a 400-acre site jointly granted by the two authorities. Since then, the University has incorporated the former Coventry College of Education in 1978 and has extended its land holdings by the purchase of adjoining farm land.

    The University initially admitted a small intake of graduate students in 1964 and took its first 450 undergraduates in October 1965. In October 2013, the student population was over 23,000 of which 9,775 are postgraduates. Around a third of the student body comes from overseas and over 120 countries are represented on the campus.

    The University of Warwick is a public research university on the outskirts of Coventry between the West Midlands and Warwickshire, England. The University was founded in 1965 as part of a government initiative to expand higher education. The Warwick Business School was established in 1967, the Warwick Law School in 1968, Warwick Manufacturing Group (WMG) in 1980, and Warwick Medical School in 2000. Warwick incorporated Coventry College of Education in 1979 and Horticulture Research International in 2004.

    Warwick is primarily based on a 290 hectares (720 acres) campus on the outskirts of Coventry, with a satellite campus in Wellesbourne and a central London base at the Shard. It is organised into three faculties — Arts, Science Engineering and Medicine, and Social Sciences — within which there are 32 departments. As of 2019, Warwick has around 26,531 full-time students and 2,492 academic and research staff. It had a consolidated income of £679.9 million in 2019/20, of which £131.7 million was from research grants and contracts. Warwick Arts Centre is a multi-venue arts complex in the university’s main campus and is the largest venue of its kind in the UK, which is not in London.

    Warwick has an average intake of 4,950 undergraduates out of 38,071 applicants (7.7 applicants per place).

    Warwick is a member of AACSB, the Association of Commonwealth Universities, the Association of MBAs, EQUIS, the European University Association, the Midlands Innovation group, the Russell Group, Sutton 13 and Universities UK. It is the only European member of the Center for Urban Science and Progress, a collaboration with New York University (US). The university has extensive commercial activities, including the University of Warwick Science Park and Warwick Manufacturing Group.

    Warwick’s alumni and staff include winners of the Nobel Prize, Turing Award, Fields Medal, Richard W. Hamming Medal, Emmy Award, Grammy, and the Padma Vibhushan, and are fellows to the British Academy, the Royal Society of Literature, the Royal Academy of Engineering, and the Royal Society. Alumni also include heads of state, government officials, leaders in intergovernmental organisations, and the current chief economist at the Bank of England. Researchers at Warwick have also made significant contributions such as the development of penicillin, music therapy, Washington Consensus, Second-wave feminism, computing standards, including ISO and ECMA, complexity theory, contract theory, and the International Political Economy as a field of study.

    Twentieth century

    The idea for a university in Warwickshire was first mooted shortly after World War II, although it was not founded for a further two decades. A partnership of the city and county councils ultimately provided the impetus for the university to be established on a 400-acre (1.6 km^2) site jointly granted by the two authorities. There was some discussion between local sponsors from both the city and county over whether it should be named after Coventry or Warwickshire. The name “University of Warwick” was adopted, even though Warwick, the county town, lies some 8 miles (13 km) to its southwest and Coventry’s city centre is only 3.5 miles (5.6 km) northeast of the campus. The establishment of the University of Warwick was given approval by the government in 1961 and it received its Royal Charter of Incorporation in 1965. Since then, the university has incorporated the former Coventry College of Education in 1979 and has extended its land holdings by the continuing purchase of adjoining farm land. The university also benefited from a substantial donation from the family of John ‘Jack’ Martin, a Coventry businessman who had made a fortune from investment in Smirnoff vodka, and which enabled the construction of the Warwick Arts Centre.

    The university initially admitted a small intake of graduate students in 1964 and took its first 450 undergraduates in October 1965. Since its establishment Warwick has expanded its grounds to 721 acres (2.9 km^2), with many modern buildings and academic facilities, lakes, and woodlands. In the 1960s and 1970s, Warwick had a reputation as a politically radical institution.

    Under Vice-Chancellor Lord Butterworth, Warwick was the first UK university to adopt a business approach to higher education, develop close links with the business community and exploit the commercial value of its research. These tendencies were discussed by British historian and then-Warwick lecturer, E. P. Thompson, in his 1970 edited book Warwick University Ltd.

    The Leicester Warwick Medical School, a new medical school based jointly at Warwick and University of Leicester (UK), opened in September 2000.

    On the recommendation of Tony Blair, Bill Clinton chose Warwick as the venue for his last major foreign policy address as US President in December 2000. Sandy Berger, Clinton’s National Security Advisor, explaining the decision in a press briefing on 7 December 2000, said that: “Warwick is one of Britain’s newest and finest research universities, singled out by Prime Minister Blair as a model both of academic excellence and independence from the government.”

    Twenty-first century

    The university was seen as a favoured institution of the Labour government during the New Labour years (1997 to 2010). It was academic partner for a number of flagship Government schemes including the National Academy for Gifted and Talented Youth and the NHS University (now defunct). Tony Blair described Warwick as “a beacon among British universities for its dynamism, quality and entrepreneurial zeal”. In a 2012 study by Virgin Media Business, Warwick was described as the most “digitally-savvy” UK university.

    In February 2001, IBM donated a new S/390 computer and software worth £2 million to Warwick, to form part of a “Grid” enabling users to remotely share computing power. In April 2004 Warwick merged with the Wellesbourne and Kirton sites of Horticulture Research International. In July 2004 Warwick was the location for an important agreement between the Labour Party and the trade unions on Labour policy and trade union law, which has subsequently become known as the “Warwick Agreement”.

    In June 2006 the new University Hospital Coventry opened, including a 102,000 sq ft (9,500 m^2) university clinical sciences building. Warwick Medical School was granted independent degree-awarding status in 2007, and the School’s partnership with the University of Leicester was dissolved in the same year. In February 2010, Lord Bhattacharyya, director and founder of the WMG unit at Warwick, made a £1 million donation to the university to support science grants and awards.

    In February 2012 Warwick and Melbourne-based Monash University (AU) announced the formation of a strategic partnership, including the creation of 10 joint senior academic posts, new dual master’s and joint doctoral degrees, and co-ordination of research programmes. In March 2012 Warwick and Queen Mary, University of London announced the creation of a strategic partnership, including research collaboration, some joint teaching of English, history and computer science undergraduates, and the creation of eight joint post-doctoral research fellowships.

    In April 2012 it was announced that Warwick would be the only European university participating in the Center for Urban Science and Progress, an applied science research institute to be based in New York consisting of an international consortium of universities and technology companies led by New York University and NYU Tandon School of Engineering (US). In August 2012, Warwick and five other Midlands-based universities — Aston University (UK), the University of Birmingham (UK), the University of Leicester (UK), Loughborough University (UK) and the University of Nottingham — formed the M5 Group, a regional bloc intended to maximise the member institutions’ research income and enable closer collaboration.

    In September 2013 it was announced that a new National Automotive Innovation Centre would be built by WMG at Warwick’s main campus at a cost of £100 million, with £50 million to be contributed by Jaguar Land Rover and £30 million by Tata Motors.

    In July 2014, the government announced that Warwick would be the host for the £1 billion Advanced Propulsion Centre, a joint venture between the Automotive Council and industry. The ten-year programme intends to position the university and the UK as leaders in the field of research into the next generation of automotive technology.

    In September 2015, Warwick celebrated its 50th anniversary (1965–2015) and was designated “University of the Year” by The Times and The Sunday Times.

    Research

    In 2013/14 Warwick had a total research income of £90.1 million, of which £33.9 million was from Research Councils; £25.9 million was from central government, local authorities and public corporations; £12.7 million was from the European Union; £7.9 million was from UK industry and commerce; £5.2 million was from UK charitable bodies; £4.0 million was from overseas sources; and £0.5 million was from other sources.

    In the 2014 UK Research Excellence Framework (REF), Warwick was again ranked 7th overall (as 2008) amongst multi-faculty institutions and was the top-ranked university in the Midlands. Some 87% of the University’s academic staff were rated as being in “world-leading” or “internationally excellent” departments with top research ratings of 4* or 3*.

    Warwick is particularly strong in the areas of decision sciences research (economics, finance, management, mathematics and statistics). For instance, researchers of the Warwick Business School have won the highest prize of the prestigious European Case Clearing House (ECCH: the equivalent of the Oscars in terms of management research).

    Warwick has established a number of stand-alone units to manage and extract commercial value from its research activities. The four most prominent examples of these units are University of Warwick Science Park; Warwick HRI; Warwick Ventures (the technology transfer arm of the University); and WMG.

     
  • richardmitnick 8:04 am on May 5, 2021 Permalink | Reply
    Tags: "Lose Yourself in This Majestic New Hubble Picture of an Entire Cluster of Galaxies", Abell 3827, AG Carinae, , , , European Space Agency (EU), , , Science Alert (AU),   

    From NASA/ESA Hubble Telescope via Science Alert (AU) : “Lose Yourself in This Majestic New Hubble Picture of an Entire Cluster of Galaxies” 

    From NASA/ESA Hubble Telescope

    via

    Science Alert (AU)

    1
    Credit: R. Massey/European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/Hubble & National Aeronautics Space Agency (US)

    We’re now used to seeing beautiful shots of space taken by the Hubble Space Telescope, but that doesn’t mean they’re not still jaw-dropping in their gorgeousness – and this picture of galaxy cluster Abell 3827 certainly fits that description.

    What you’re looking at here is a cluster of hundreds of galaxies of different shapes and sizes, some 1.4 billion light-years away from Earth, with the elliptical ESO 146-5 galaxy at the center – thought to be one of the most massive in the known Universe because of its strong gravitational lensing effect (shown by the uneven blue halo).

    Light across four different wavelengths was captured and combined to produce this truly stunning image, and the more you look at it, the better it gets.

    The Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) on board Hubble were both used in capturing what you see here.

    3
    Credit: R. Massey/ESA/Hubble & NASA.

    “Looking at this cluster of hundreds of galaxies, it is amazing to recall that until less than 100 years ago, many astronomers believed that the Milky Way was the only galaxy in the Universe,” writes the European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU) team that published the picture.

    “The possibility of other galaxies had been debated previously, but the matter was not truly settled until Edwin Hubble confirmed that the Great Andromeda Nebula was in fact far too distant to be part of the Milky Way.”

    Andromeda Galaxy. Credit: Adam Evans.

    Abell 3827 is of particularly interest to astronomers because it’s thought to contain pockets of dark matter – the elusive and invisible mass that could make up as much as 85 percent of the total amount of material in existence.

    While studies of Abell 3827 and other galaxy clusters like it continue, we’re happy to just sit back in awe at the scale and the quality of the image that the Hubble telescope has managed to produce here.

    The telescope just celebrated 31 years of snapping the celestial skies, releasing an image of the giant, ultra-bright star AG Carinae as it battles against self destruction – a star some 70 times bigger and 1 million times brighter than our own Sun.

    4
    AG Carinae Credit: NASA, ESA, NASA Space Telescope Science Institute (US))

    Last year, for Hubble’s 30th birthday, we were treated to a whole cascade of new photos released to mark the occasion. Since heading into space in April 1990, the telescope has taken around 1.5 million snaps of roughly 48,000 stars, planets and galaxies.

    Even with such a rich catalog to its name, we think this latest image might be one of our favorites of the whole Hubble Space Telescope collection – and as research into dark matter continues, expect to hear more about Abell 3827 along the way.

    You can read more about the image on the ESA website.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The NASA/ESA Hubble Space Telescope is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA’s Great Observatories, along with the NASA Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the NASA Spitzer Infared Space Telescope.



    Edwin Hubble at Caltech Palomar Samuel Oschin 48 inch Telescope(US). Credit: Emilio Segre Visual Archives/AIP/SPL).

    Hubble features a 2.4-meter (7.9 ft) mirror, and its four main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble’s orbit outside the distortion of Earth’s atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detailed visible light images, allowing a deep view into space. Many Hubble observations have led to breakthroughs in astrophysics, such as determining the rate of expansion of the universe.

    The Hubble telescope was built by the United States space agency National Aeronautics Space Agency(US) with contributions from the European Space Agency [Agence spatiale européenne](EU). The Space Telescope Science Institute (STScI) selects Hubble’s targets and processes the resulting data, while the NASA Goddard Space Flight Center(US) controls the spacecraft. Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the 1986 Challenger disaster. It was finally launched by Space Shuttle Discovery in 1990, but its main mirror had been ground incorrectly, resulting in spherical aberration that compromised the telescope’s capabilities. The optics were corrected to their intended quality by a servicing mission in 1993.

    Hubble is the only telescope designed to be maintained in space by astronauts. Five Space Shuttle missions have repaired, upgraded, and replaced systems on the telescope, including all five of the main instruments. The fifth mission was initially canceled on safety grounds following the Columbia disaster (2003), but NASA administrator Michael D. Griffin approved the fifth servicing mission which was completed in 2009. The telescope was still operating as of April 24, 2020, its 30th anniversary, and could last until 2030–2040. One successor to the Hubble telescope is the National Aeronautics Space Agency(USA)/European Space Agency [Agence spatiale européenne](EU)/Canadian Space Agency(CA) Webb Infrared Space Telescope scheduled for launch in October 2021.

    Proposals and precursors

    In 1923, Hermann Oberth—considered a father of modern rocketry, along with Robert H. Goddard and Konstantin Tsiolkovsky—published Die Rakete zu den Planetenräumen (“The Rocket into Planetary Space“), which mentioned how a telescope could be propelled into Earth orbit by a rocket.

    The history of the Hubble Space Telescope can be traced back as far as 1946, to astronomer Lyman Spitzer’s paper entitled Astronomical advantages of an extraterrestrial observatory. In it, he discussed the two main advantages that a space-based observatory would have over ground-based telescopes. First, the angular resolution (the smallest separation at which objects can be clearly distinguished) would be limited only by diffraction, rather than by the turbulence in the atmosphere, which causes stars to twinkle, known to astronomers as seeing. At that time ground-based telescopes were limited to resolutions of 0.5–1.0 arcseconds, compared to a theoretical diffraction-limited resolution of about 0.05 arcsec for an optical telescope with a mirror 2.5 m (8.2 ft) in diameter. Second, a space-based telescope could observe infrared and ultraviolet light, which are strongly absorbed by the atmosphere.

    Spitzer devoted much of his career to pushing for the development of a space telescope. In 1962, a report by the U.S. National Academy of Sciences recommended development of a space telescope as part of the space program, and in 1965 Spitzer was appointed as head of a committee given the task of defining scientific objectives for a large space telescope.

    Space-based astronomy had begun on a very small scale following World War II, as scientists made use of developments that had taken place in rocket technology. The first ultraviolet spectrum of the Sun was obtained in 1946, and the National Aeronautics and Space Administration (US) launched the Orbiting Solar Observatory (OSO) to obtain UV, X-ray, and gamma-ray spectra in 1962.

    An orbiting solar telescope was launched in 1962 by the United Kingdom as part of the Ariel space program, and in 1966 NASA launched the first Orbiting Astronomical Observatory (OAO) mission. OAO-1’s battery failed after three days, terminating the mission. It was followed by OAO-2, which carried out ultraviolet observations of stars and galaxies from its launch in 1968 until 1972, well beyond its original planned lifetime of one year.

    The OSO and OAO missions demonstrated the important role space-based observations could play in astronomy. In 1968, NASA developed firm plans for a space-based reflecting telescope with a mirror 3 m (9.8 ft) in diameter, known provisionally as the Large Orbiting Telescope or Large Space Telescope (LST), with a launch slated for 1979. These plans emphasized the need for crewed maintenance missions to the telescope to ensure such a costly program had a lengthy working life, and the concurrent development of plans for the reusable Space Shuttle indicated that the technology to allow this was soon to become available.

    Quest for funding

    The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established, the next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The U.S. Congress questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974, public spending cuts led to Congress deleting all funding for the telescope project.
    In response a nationwide lobbying effort was coordinated among astronomers. Many astronomers met congressmen and senators in person, and large scale letter-writing campaigns were organized. The National Academy of Sciences published a report emphasizing the need for a space telescope, and eventually the Senate agreed to half the budget that had originally been approved by Congress.

    The funding issues led to something of a reduction in the scale of the project, with the proposed mirror diameter reduced from 3 m to 2.4 m, both to cut costs and to allow a more compact and effective configuration for the telescope hardware. A proposed precursor 1.5 m (4.9 ft) space telescope to test the systems to be used on the main satellite was dropped, and budgetary concerns also prompted collaboration with the European Space Agency. ESA agreed to provide funding and supply one of the first generation instruments for the telescope, as well as the solar cells that would power it, and staff to work on the telescope in the United States, in return for European astronomers being guaranteed at least 15% of the observing time on the telescope. Congress eventually approved funding of US$36 million for 1978, and the design of the LST began in earnest, aiming for a launch date of 1983. In 1983 the telescope was named after Edwin Hubble, who confirmed one of the greatest scientific discoveries of the 20th century, made by Georges Lemaître, that the universe is expanding.

    Construction and engineering

    Once the Space Telescope project had been given the go-ahead, work on the program was divided among many institutions. NASA Marshall Space Flight Center (MSFC) was given responsibility for the design, development, and construction of the telescope, while Goddard Space Flight Center was given overall control of the scientific instruments and ground-control center for the mission. MSFC commissioned the optics company Perkin-Elmer to design and build the Optical Telescope Assembly (OTA) and Fine Guidance Sensors for the space telescope. Lockheed was commissioned to construct and integrate the spacecraft in which the telescope would be housed.

    Optical Telescope Assembly

    Optically, the HST is a Cassegrain reflector of Ritchey–Chrétien design, as are most large professional telescopes. This design, with two hyperbolic mirrors, is known for good imaging performance over a wide field of view, with the disadvantage that the mirrors have shapes that are hard to fabricate and test. The mirror and optical systems of the telescope determine the final performance, and they were designed to exacting specifications. Optical telescopes typically have mirrors polished to an accuracy of about a tenth of the wavelength of visible light, but the Space Telescope was to be used for observations from the visible through the ultraviolet (shorter wavelengths) and was specified to be diffraction limited to take full advantage of the space environment. Therefore, its mirror needed to be polished to an accuracy of 10 nanometers, or about 1/65 of the wavelength of red light. On the long wavelength end, the OTA was not designed with optimum IR performance in mind—for example, the mirrors are kept at stable (and warm, about 15 °C) temperatures by heaters. This limits Hubble’s performance as an infrared telescope.

    Perkin-Elmer intended to use custom-built and extremely sophisticated computer-controlled polishing machines to grind the mirror to the required shape. However, in case their cutting-edge technology ran into difficulties, NASA demanded that PE sub-contract to Kodak to construct a back-up mirror using traditional mirror-polishing techniques. (The team of Kodak and Itek also bid on the original mirror polishing work. Their bid called for the two companies to double-check each other’s work, which would have almost certainly caught the polishing error that later caused such problems.) The Kodak mirror is now on permanent display at the National Air and Space Museum. An Itek mirror built as part of the effort is now used in the 2.4 m telescope at the Magdalena Ridge Observatory.

    Construction of the Perkin-Elmer mirror began in 1979, starting with a blank manufactured by Corning from their ultra-low expansion glass. To keep the mirror’s weight to a minimum it consisted of top and bottom plates, each one inch (25 mm) thick, sandwiching a honeycomb lattice. Perkin-Elmer simulated microgravity by supporting the mirror from the back with 130 rods that exerted varying amounts of force. This ensured the mirror’s final shape would be correct and to specification when finally deployed. Mirror polishing continued until May 1981. NASA reports at the time questioned Perkin-Elmer’s managerial structure, and the polishing began to slip behind schedule and over budget. To save money, NASA halted work on the back-up mirror and put the launch date of the telescope back to October 1984. The mirror was completed by the end of 1981; it was washed using 2,400 US gallons (9,100 L) of hot, deionized water and then received a reflective coating of 65 nm-thick aluminum and a protective coating of 25 nm-thick magnesium fluoride.

    Doubts continued to be expressed about Perkin-Elmer’s competence on a project of this importance, as their budget and timescale for producing the rest of the OTA continued to inflate. In response to a schedule described as “unsettled and changing daily”, NASA postponed the launch date of the telescope until April 1985. Perkin-Elmer’s schedules continued to slip at a rate of about one month per quarter, and at times delays reached one day for each day of work. NASA was forced to postpone the launch date until March and then September 1986. By this time, the total project budget had risen to US$1.175 billion.

    Spacecraft systems

    The spacecraft in which the telescope and instruments were to be housed was another major engineering challenge. It would have to withstand frequent passages from direct sunlight into the darkness of Earth’s shadow, which would cause major changes in temperature, while being stable enough to allow extremely accurate pointing of the telescope. A shroud of multi-layer insulation keeps the temperature within the telescope stable and surrounds a light aluminum shell in which the telescope and instruments sit. Within the shell, a graphite-epoxy frame keeps the working parts of the telescope firmly aligned. Because graphite composites are hygroscopic, there was a risk that water vapor absorbed by the truss while in Lockheed’s clean room would later be expressed in the vacuum of space; resulting in the telescope’s instruments being covered by ice. To reduce that risk, a nitrogen gas purge was performed before launching the telescope into space.

    While construction of the spacecraft in which the telescope and instruments would be housed proceeded somewhat more smoothly than the construction of the OTA, Lockheed still experienced some budget and schedule slippage, and by the summer of 1985, construction of the spacecraft was 30% over budget and three months behind schedule. An MSFC report said Lockheed tended to rely on NASA directions rather than take their own initiative in the construction.

    Computer systems and data processing

    The two initial, primary computers on the HST were the 1.25 MHz DF-224 system, built by Rockwell Autonetics, which contained three redundant CPUs, and two redundant NSSC-1 (NASA Standard Spacecraft Computer, Model 1) systems, developed by Westinghouse and GSFC using diode–transistor logic (DTL). A co-processor for the DF-224 was added during Servicing Mission 1 in 1993, which consisted of two redundant strings of an Intel-based 80386 processor with an 80387 math co-processor. The DF-224 and its 386 co-processor were replaced by a 25 MHz Intel-based 80486 processor system during Servicing Mission 3A in 1999. The new computer is 20 times faster, with six times more memory, than the DF-224 it replaced. It increases throughput by moving some computing tasks from the ground to the spacecraft and saves money by allowing the use of modern programming languages.

    Additionally, some of the science instruments and components had their own embedded microprocessor-based control systems. The MATs (Multiple Access Transponder) components, MAT-1 and MAT-2, utilize Hughes Aircraft CDP1802CD microprocessors. The Wide Field and Planetary Camera (WFPC) also utilized an RCA 1802 microprocessor (or possibly the older 1801 version). The WFPC-1 was replaced by the WFPC-2 [below] during Servicing Mission 1 in 1993, which was then replaced by the Wide Field Camera 3 (WFC3) [below] during Servicing Mission 4 in 2009.

    Initial instruments

    When launched, the HST carried five scientific instruments: the Wide Field and Planetary Camera (WF/PC), Goddard High Resolution Spectrograph (GHRS), High Speed Photometer (HSP), Faint Object Camera (FOC) and the Faint Object Spectrograph (FOS). WF/PC was a high-resolution imaging device primarily intended for optical observations. It was built by NASA JPL-Caltech(US), and incorporated a set of 48 filters isolating spectral lines of particular astrophysical interest. The instrument contained eight charge-coupled device (CCD) chips divided between two cameras, each using four CCDs. Each CCD has a resolution of 0.64 megapixels. The wide field camera (WFC) covered a large angular field at the expense of resolution, while the planetary camera (PC) took images at a longer effective focal length than the WF chips, giving it a greater magnification.

    The GHRS was a spectrograph designed to operate in the ultraviolet. It was built by the Goddard Space Flight Center and could achieve a spectral resolution of 90,000. Also optimized for ultraviolet observations were the FOC and FOS, which were capable of the highest spatial resolution of any instruments on Hubble. Rather than CCDs these three instruments used photon-counting digicons as their detectors. The FOC was constructed by ESA, while the University of California, San Diego(US), and Martin Marietta Corporation built the FOS.

    The final instrument was the HSP, designed and built at the University of Wisconsin–Madison(US). It was optimized for visible and ultraviolet light observations of variable stars and other astronomical objects varying in brightness. It could take up to 100,000 measurements per second with a photometric accuracy of about 2% or better.

    HST’s guidance system can also be used as a scientific instrument. Its three Fine Guidance Sensors (FGS) are primarily used to keep the telescope accurately pointed during an observation, but can also be used to carry out extremely accurate astrometry; measurements accurate to within 0.0003 arcseconds have been achieved.

    Ground support

    The Space Telescope Science Institute (STScI) is responsible for the scientific operation of the telescope and the delivery of data products to astronomers. STScI is operated by the Association of Universities for Research in Astronomy(US) (AURA) and is physically located in Baltimore, Maryland on the Homewood campus of Johns Hopkins University(US), one of the 39 U.S. universities and seven international affiliates that make up the AURA consortium. STScI was established in 1981 after something of a power struggle between NASA and the scientific community at large. NASA had wanted to keep this function in-house, but scientists wanted it to be based in an academic establishment. The Space Telescope European Coordinating Facility (ST-ECF), established at Garching bei München near Munich in 1984, provided similar support for European astronomers until 2011, when these activities were moved to the European Space Astronomy Centre.

    One rather complex task that falls to STScI is scheduling observations for the telescope. Hubble is in a low-Earth orbit to enable servicing missions, but this means most astronomical targets are occulted by the Earth for slightly less than half of each orbit. Observations cannot take place when the telescope passes through the South Atlantic Anomaly due to elevated radiation levels, and there are also sizable exclusion zones around the Sun (precluding observations of Mercury), Moon and Earth. The solar avoidance angle is about 50°, to keep sunlight from illuminating any part of the OTA. Earth and Moon avoidance keeps bright light out of the FGSs, and keeps scattered light from entering the instruments. If the FGSs are turned off, the Moon and Earth can be observed. Earth observations were used very early in the program to generate flat-fields for the WFPC1 instrument. There is a so-called continuous viewing zone (CVZ), at roughly 90° to the plane of Hubble’s orbit, in which targets are not occulted for long periods.

    Challenger disaster, delays, and eventual launch

    By January 1986, the planned launch date of October looked feasible, but the Challenger explosion brought the U.S. space program to a halt, grounding the Shuttle fleet and forcing the launch of Hubble to be postponed for several years. The telescope had to be kept in a clean room, powered up and purged with nitrogen, until a launch could be rescheduled. This costly situation (about US$6 million per month) pushed the overall costs of the project even higher. This delay did allow time for engineers to perform extensive tests, swap out a possibly failure-prone battery, and make other improvements. Furthermore, the ground software needed to control Hubble was not ready in 1986, and was barely ready by the 1990 launch.

    Eventually, following the resumption of shuttle flights in 1988, the launch of the telescope was scheduled for 1990. On April 24, 1990, Space Shuttle Discovery successfully launched it during the STS-31 mission.

    From its original total cost estimate of about US$400 million, the telescope cost about US$4.7 billion by the time of its launch. Hubble’s cumulative costs were estimated to be about US$10 billion in 2010, twenty years after launch.

    List of Hubble instruments

    Hubble accommodates five science instruments at a given time, plus the Fine Guidance Sensors, which are mainly used for aiming the telescope but are occasionally used for scientific astrometry measurements. Early instruments were replaced with more advanced ones during the Shuttle servicing missions. COSTAR was a corrective optics device rather than a science instrument, but occupied one of the five instrument bays.
    Since the final servicing mission in 2009, the four active instruments have been ACS, COS, STIS and WFC3. NICMOS is kept in hibernation, but may be revived if WFC3 were to fail in the future.

    Advanced Camera for Surveys (ACS; 2002–present)
    Cosmic Origins Spectrograph (COS; 2009–present)
    Corrective Optics Space Telescope Axial Replacement (COSTAR; 1993–2009)
    Faint Object Camera (FOC; 1990–2002)
    Faint Object Spectrograph (FOS; 1990–1997)
    Fine Guidance Sensor (FGS; 1990–present)
    Goddard High Resolution Spectrograph (GHRS/HRS; 1990–1997)
    High Speed Photometer (HSP; 1990–1993)
    Near Infrared Camera and Multi-Object Spectrometer (NICMOS; 1997–present, hibernating since 2008)
    Space Telescope Imaging Spectrograph (STIS; 1997–present (non-operative 2004–2009))
    Wide Field and Planetary Camera (WFPC; 1990–1993)
    Wide Field and Planetary Camera 2 (WFPC2; 1993–2009)
    Wide Field Camera 3 (WFC3; 2009–present)

    Of the former instruments, three (COSTAR, FOS and WFPC2) are displayed in the Smithsonian National Air and Space Museum. The FOC is in the Dornier museum, Germany. The HSP is in the Space Place at the University of Wisconsin–Madison. The first WFPC was dismantled, and some components were then re-used in WFC3.

    Flawed mirror

    Within weeks of the launch of the telescope, the returned images indicated a serious problem with the optical system. Although the first images appeared to be sharper than those of ground-based telescopes, Hubble failed to achieve a final sharp focus and the best image quality obtained was drastically lower than expected. Images of point sources spread out over a radius of more than one arcsecond, instead of having a point spread function (PSF) concentrated within a circle 0.1 arcseconds (485 nrad) in diameter, as had been specified in the design criteria.

    Analysis of the flawed images revealed that the primary mirror had been polished to the wrong shape. Although it was believed to be one of the most precisely figured optical mirrors ever made, smooth to about 10 nanometers, the outer perimeter was too flat by about 2200 nanometers (about 1⁄450 mm or 1⁄11000 inch). This difference was catastrophic, introducing severe spherical aberration, a flaw in which light reflecting off the edge of a mirror focuses on a different point from the light reflecting off its center.

    The effect of the mirror flaw on scientific observations depended on the particular observation—the core of the aberrated PSF was sharp enough to permit high-resolution observations of bright objects, and spectroscopy of point sources was affected only through a sensitivity loss. However, the loss of light to the large, out-of-focus halo severely reduced the usefulness of the telescope for faint objects or high-contrast imaging. This meant nearly all the cosmological programs were essentially impossible, since they required observation of exceptionally faint objects. This led politicians to question NASA’s competence, scientists to rue the cost which could have gone to more productive endeavors, and comedians to make jokes about NASA and the telescope − in the 1991 comedy The Naked Gun 2½: The Smell of Fear, in a scene where historical disasters are displayed, Hubble is pictured with RMS Titanic and LZ 129 Hindenburg. Nonetheless, during the first three years of the Hubble mission, before the optical corrections, the telescope still carried out a large number of productive observations of less demanding targets. The error was well characterized and stable, enabling astronomers to partially compensate for the defective mirror by using sophisticated image processing techniques such as deconvolution.

    Origin of the problem

    A commission headed by Lew Allen, director of the Jet Propulsion Laboratory, was established to determine how the error could have arisen. The Allen Commission found that a reflective null corrector, a testing device used to achieve a properly shaped non-spherical mirror, had been incorrectly assembled—one lens was out of position by 1.3 mm (0.051 in). During the initial grinding and polishing of the mirror, Perkin-Elmer analyzed its surface with two conventional refractive null correctors. However, for the final manufacturing step (figuring), they switched to the custom-built reflective null corrector, designed explicitly to meet very strict tolerances. The incorrect assembly of this device resulted in the mirror being ground very precisely but to the wrong shape. A few final tests, using the conventional null correctors, correctly reported spherical aberration. But these results were dismissed, thus missing the opportunity to catch the error, because the reflective null corrector was considered more accurate.

    The commission blamed the failings primarily on Perkin-Elmer. Relations between NASA and the optics company had been severely strained during the telescope construction, due to frequent schedule slippage and cost overruns. NASA found that Perkin-Elmer did not review or supervise the mirror construction adequately, did not assign its best optical scientists to the project (as it had for the prototype), and in particular did not involve the optical designers in the construction and verification of the mirror. While the commission heavily criticized Perkin-Elmer for these managerial failings, NASA was also criticized for not picking up on the quality control shortcomings, such as relying totally on test results from a single instrument.

    Design of a solution

    Many feared that Hubble would be abandoned. The design of the telescope had always incorporated servicing missions, and astronomers immediately began to seek potential solutions to the problem that could be applied at the first servicing mission, scheduled for 1993. While Kodak had ground a back-up mirror for Hubble, it would have been impossible to replace the mirror in orbit, and too expensive and time-consuming to bring the telescope back to Earth for a refit. Instead, the fact that the mirror had been ground so precisely to the wrong shape led to the design of new optical components with exactly the same error but in the opposite sense, to be added to the telescope at the servicing mission, effectively acting as “spectacles” to correct the spherical aberration.

    The first step was a precise characterization of the error in the main mirror. Working backwards from images of point sources, astronomers determined that the conic constant of the mirror as built was −1.01390±0.0002, instead of the intended −1.00230. The same number was also derived by analyzing the null corrector used by Perkin-Elmer to figure the mirror, as well as by analyzing interferograms obtained during ground testing of the mirror.

    Because of the way the HST’s instruments were designed, two different sets of correctors were required. The design of the Wide Field and Planetary Camera 2, already planned to replace the existing WF/PC, included relay mirrors to direct light onto the four separate charge-coupled device (CCD) chips making up its two cameras. An inverse error built into their surfaces could completely cancel the aberration of the primary. However, the other instruments lacked any intermediate surfaces that could be figured in this way, and so required an external correction device.

    The Corrective Optics Space Telescope Axial Replacement (COSTAR) system was designed to correct the spherical aberration for light focused at the FOC, FOS, and GHRS. It consists of two mirrors in the light path with one ground to correct the aberration. To fit the COSTAR system onto the telescope, one of the other instruments had to be removed, and astronomers selected the High Speed Photometer to be sacrificed. By 2002, all the original instruments requiring COSTAR had been replaced by instruments with their own corrective optics. COSTAR was removed and returned to Earth in 2009 where it is exhibited at the National Air and Space Museum. The area previously used by COSTAR is now occupied by the Cosmic Origins Spectrograph.

    Servicing missions and new instruments

    Servicing Mission 1

    The first Hubble serving mission was scheduled for 1993 before the mirror problem was discovered. It assumed greater importance, as the astronauts would need to do extensive work to install corrective optics; failure would have resulted in either abandoning Hubble or accepting its permanent disability. Other components failed before the mission, causing the repair cost to rise to $500 million (not including the cost of the shuttle flight). A successful repair would help demonstrate the viability of building Space Station Alpha, however.

    STS-49 in 1992 demonstrated the difficulty of space work. While its rescue of Intelsat 603 received praise, the astronauts had taken possibly reckless risks in doing so. Neither the rescue nor the unrelated assembly of prototype space station components occurred as the astronauts had trained, causing NASA to reassess planning and training, including for the Hubble repair. The agency assigned to the mission Story Musgrave—who had worked on satellite repair procedures since 1976—and six other experienced astronauts, including two from STS-49. The first mission director since Project Apollo would coordinate a crew with 16 previous shuttle flights. The astronauts were trained to use about a hundred specialized tools.

    Heat had been the problem on prior spacewalks, which occurred in sunlight. Hubble needed to be repaired out of sunlight. Musgrave discovered during vacuum training, seven months before the mission, that spacesuit gloves did not sufficiently protect against the cold of space. After STS-57 confirmed the issue in orbit, NASA quickly changed equipment, procedures, and flight plan. Seven total mission simulations occurred before launch, the most thorough preparation in shuttle history. No complete Hubble mockup existed, so the astronauts studied many separate models (including one at the Smithsonian) and mentally combined their varying and contradictory details. Service Mission 1 flew aboard Endeavour in December 1993, and involved installation of several instruments and other equipment over ten days.

    Most importantly, the High Speed Photometer was replaced with the COSTAR corrective optics package, and WFPC was replaced with the Wide Field and Planetary Camera 2 (WFPC2) with an internal optical correction system. The solar arrays and their drive electronics were also replaced, as well as four gyroscopes in the telescope pointing system, two electrical control units and other electrical components, and two magnetometers. The onboard computers were upgraded with added coprocessors, and Hubble’s orbit was boosted.

    On January 13, 1994, NASA declared the mission a complete success and showed the first sharper images. The mission was one of the most complex performed up until that date, involving five long extra-vehicular activity periods. Its success was a boon for NASA, as well as for the astronomers who now had a more capable space telescope.

    Servicing Mission 2

    Servicing Mission 2, flown by Discovery in February 1997, replaced the GHRS and the FOS with the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), replaced an Engineering and Science Tape Recorder with a new Solid State Recorder, and repaired thermal insulation. NICMOS contained a heat sink of solid nitrogen to reduce the thermal noise from the instrument, but shortly after it was installed, an unexpected thermal expansion resulted in part of the heat sink coming into contact with an optical baffle. This led to an increased warming rate for the instrument and reduced its original expected lifetime of 4.5 years to about two years.

    Servicing Mission 3A

    Servicing Mission 3A, flown by Discovery, took place in December 1999, and was a split-off from Servicing Mission 3 after three of the six onboard gyroscopes had failed. The fourth failed a few weeks before the mission, rendering the telescope incapable of performing scientific observations. The mission replaced all six gyroscopes, replaced a Fine Guidance Sensor and the computer, installed a Voltage/temperature Improvement Kit (VIK) to prevent battery overcharging, and replaced thermal insulation blankets.

    Servicing Mission 3B

    Servicing Mission 3B flown by Columbia in March 2002 saw the installation of a new instrument, with the FOC (which, except for the Fine Guidance Sensors when used for astrometry, was the last of the original instruments) being replaced by the Advanced Camera for Surveys (ACS). This meant COSTAR was no longer required, since all new instruments had built-in correction for the main mirror aberration. The mission also revived NICMOS by installing a closed-cycle cooler and replaced the solar arrays for the second time, providing 30 percent more power.

    Servicing Mission 4

    Plans called for Hubble to be serviced in February 2005, but the Columbia disaster in 2003, in which the orbiter disintegrated on re-entry into the atmosphere, had wide-ranging effects on the Hubble program. NASA Administrator Sean O’Keefe decided all future shuttle missions had to be able to reach the safe haven of the International Space Station should in-flight problems develop. As no shuttles were capable of reaching both HST and the space station during the same mission, future crewed service missions were canceled. This decision was criticised by numerous astronomers who felt Hubble was valuable enough to merit the human risk. HST’s planned successor, the James Webb Telescope (JWST), as of 2004 was not expected to launch until at least 2011. A gap in space-observing capabilities between a decommissioning of Hubble and the commissioning of a successor was of major concern to many astronomers, given the significant scientific impact of HST. The consideration that JWST will not be located in low Earth orbit, and therefore cannot be easily upgraded or repaired in the event of an early failure, only made concerns more acute. On the other hand, many astronomers felt strongly that servicing Hubble should not take place if the expense were to come from the JWST budget.

    In January 2004, O’Keefe said he would review his decision to cancel the final servicing mission to HST, due to public outcry and requests from Congress for NASA to look for a way to save it. The National Academy of Sciences convened an official panel, which recommended in July 2004 that the HST should be preserved despite the apparent risks. Their report urged “NASA should take no actions that would preclude a space shuttle servicing mission to the Hubble Space Telescope”. In August 2004, O’Keefe asked Goddard Space Flight Center to prepare a detailed proposal for a robotic service mission. These plans were later canceled, the robotic mission being described as “not feasible”. In late 2004, several Congressional members, led by Senator Barbara Mikulski, held public hearings and carried on a fight with much public support (including thousands of letters from school children across the U.S.) to get the Bush Administration and NASA to reconsider the decision to drop plans for a Hubble rescue mission.

    The nomination in April 2005 of a new NASA Administrator, Michael D. Griffin, changed the situation, as Griffin stated he would consider a crewed servicing mission. Soon after his appointment Griffin authorized Goddard to proceed with preparations for a crewed Hubble maintenance flight, saying he would make the final decision after the next two shuttle missions. In October 2006 Griffin gave the final go-ahead, and the 11-day mission by Atlantis was scheduled for October 2008. Hubble’s main data-handling unit failed in September 2008, halting all reporting of scientific data until its back-up was brought online on October 25, 2008. Since a failure of the backup unit would leave the HST helpless, the service mission was postponed to incorporate a replacement for the primary unit.

    Servicing Mission 4 (SM4), flown by Atlantis in May 2009, was the last scheduled shuttle mission for HST. SM4 installed the replacement data-handling unit, repaired the ACS and STIS systems, installed improved nickel hydrogen batteries, and replaced other components including all six gyroscopes. SM4 also installed two new observation instruments—Wide Field Camera 3 (WFC3) and the Cosmic Origins Spectrograph (COS)—and the Soft Capture and Rendezvous System, which will enable the future rendezvous, capture, and safe disposal of Hubble by either a crewed or robotic mission. Except for the ACS’s High Resolution Channel, which could not be repaired and was disabled, the work accomplished during SM4 rendered the telescope fully functional.

    Major projects

    Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey [CANDELS]

    The survey “aims to explore galactic evolution in the early Universe, and the very first seeds of cosmic structure at less than one billion years after the Big Bang.” The CANDELS project site describes the survey’s goals as the following:

    The Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey is designed to document the first third of galactic evolution from z = 8 to 1.5 via deep imaging of more than 250,000 galaxies with WFC3/IR and ACS. It will also find the first Type Ia SNe beyond z > 1.5 and establish their accuracy as standard candles for cosmology. Five premier multi-wavelength sky regions are selected; each has multi-wavelength data from Spitzer and other facilities, and has extensive spectroscopy of the brighter galaxies. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to 109 solar masses out to z ~ 8.

    Frontier Fields program

    The program, officially named Hubble Deep Fields Initiative 2012, is aimed to advance the knowledge of early galaxy formation by studying high-redshift galaxies in blank fields with the help of gravitational lensing to see the “faintest galaxies in the distant universe”. The Frontier Fields web page describes the goals of the program being:

    To reveal hitherto inaccessible populations of z = 5–10 galaxies that are ten to fifty times fainter intrinsically than any presently known
    To solidify our understanding of the stellar masses and star formation histories of sub-L* galaxies at the earliest times
    To provide the first statistically meaningful morphological characterization of star forming galaxies at z > 5
    To find z > 8 galaxies stretched out enough by cluster lensing to discern internal structure and/or magnified enough by cluster lensing for spectroscopic follow-up.

    Cosmic Evolution Survey (COSMOS)

    The Cosmic Evolution Survey (COSMOS) is an astronomical survey designed to probe the formation and evolution of galaxies as a function of both cosmic time (redshift) and the local galaxy environment. The survey covers a two square degree equatorial field with spectroscopy and X-ray to radio imaging by most of the major space-based telescopes and a number of large ground based telescopes, making it a key focus region of extragalactic astrophysics. COSMOS was launched in 2006 as the largest project pursued by the Hubble Space Telescope at the time, and still is the largest continuous area of sky covered for the purposes of mapping deep space in blank fields, 2.5 times the area of the moon on the sky and 17 times larger than the largest of the CANDELS regions. The COSMOS scientific collaboration that was forged from the initial COSMOS survey is the largest and longest-running extragalactic collaboration, known for its collegiality and openness. The study of galaxies in their environment can be done only with large areas of the sky, larger than a half square degree. More than two million galaxies are detected, spanning 90% of the age of the Universe. The COSMOS collaboration is led by Caitlin Casey, Jeyhan Kartaltepe, and Vernesa Smolcic and involves more than 200 scientists in a dozen countries.

    Important discoveries

    Hubble has helped resolve some long-standing problems in astronomy, while also raising new questions. Some results have required new theories to explain them.

    Age of the universe

    Among its primary mission targets was to measure distances to Cepheid variable stars more accurately than ever before, and thus constrain the value of the Hubble constant, the measure of the rate at which the universe is expanding, which is also related to its age. Before the launch of HST, estimates of the Hubble constant typically had errors of up to 50%, but Hubble measurements of Cepheid variables in the Virgo Cluster and other distant galaxy clusters provided a measured value with an accuracy of ±10%, which is consistent with other more accurate measurements made since Hubble’s launch using other techniques. The estimated age is now about 13.7 billion years, but before the Hubble Telescope, scientists predicted an age ranging from 10 to 20 billion years.

    Expansion of the universe

    While Hubble helped to refine estimates of the age of the universe, it also cast doubt on theories about its future. Astronomers from the High-z Supernova Search Team and the Supernova Cosmology Project used ground-based telescopes and HST to observe distant supernovae and uncovered evidence that, far from decelerating under the influence of gravity, the expansion of the universe may in fact be accelerating. Three members of these two groups have subsequently been awarded Nobel Prizes for their discovery.

    Saul Perlmutter [The Supernova Cosmology Project] shared the 2006 Shaw Prize in Astronomy, the 2011 Nobel Prize in Physics, and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess [The High-z Supernova Search Team] for providing evidence that the expansion of the universe is accelerating.

    The cause of this acceleration remains poorly understood; the most common cause attributed is Dark Energy.

    Black holes

    The high-resolution spectra and images provided by the HST have been especially well-suited to establishing the prevalence of black holes in the center of nearby galaxies. While it had been hypothesized in the early 1960s that black holes would be found at the centers of some galaxies, and astronomers in the 1980s identified a number of good black hole candidates, work conducted with Hubble shows that black holes are probably common to the centers of all galaxies. The Hubble programs further established that the masses of the nuclear black holes and properties of the galaxies are closely related. The legacy of the Hubble programs on black holes in galaxies is thus to demonstrate a deep connection between galaxies and their central black holes.

    Extending visible wavelength images

    A unique window on the Universe enabled by Hubble are the Hubble Deep Field, Hubble Ultra-Deep Field, and Hubble Extreme Deep Field images, which used Hubble’s unmatched sensitivity at visible wavelengths to create images of small patches of sky that are the deepest ever obtained at optical wavelengths. The images reveal galaxies billions of light years away, and have generated a wealth of scientific papers, providing a new window on the early Universe. The Wide Field Camera 3 improved the view of these fields in the infrared and ultraviolet, supporting the discovery of some of the most distant objects yet discovered, such as MACS0647-JD.

    The non-standard object SCP 06F6 was discovered by the Hubble Space Telescope in February 2006.

    On March 3, 2016, researchers using Hubble data announced the discovery of the farthest known galaxy to date: GN-z11. The Hubble observations occurred on February 11, 2015, and April 3, 2015, as part of the CANDELS/GOODS-North surveys.

    Solar System discoveries

    HST has also been used to study objects in the outer reaches of the Solar System, including the dwarf planets Pluto and Eris.

    The collision of Comet Shoemaker-Levy 9 with Jupiter in 1994 was fortuitously timed for astronomers, coming just a few months after Servicing Mission 1 had restored Hubble’s optical performance. Hubble images of the planet were sharper than any taken since the passage of Voyager 2 in 1979, and were crucial in studying the dynamics of the collision of a comet with Jupiter, an event believed to occur once every few centuries.

    During June and July 2012, U.S. astronomers using Hubble discovered Styx, a tiny fifth moon orbiting Pluto.

    In March 2015, researchers announced that measurements of aurorae around Ganymede, one of Jupiter’s moons, revealed that it has a subsurface ocean. Using Hubble to study the motion of its aurorae, the researchers determined that a large saltwater ocean was helping to suppress the interaction between Jupiter’s magnetic field and that of Ganymede. The ocean is estimated to be 100 km (60 mi) deep, trapped beneath a 150 km (90 mi) ice crust.

    From June to August 2015, Hubble was used to search for a Kuiper belt object (KBO) target for the New Horizons Kuiper Belt Extended Mission (KEM) when similar searches with ground telescopes failed to find a suitable target.

    This resulted in the discovery of at least five new KBOs, including the eventual KEM target, 486958 Arrokoth, that New Horizons performed a close fly-by of on January 1, 2019.

    In August 2020, taking advantage of a total lunar eclipse, astronomers using NASA’s Hubble Space Telescope have detected Earth’s own brand of sunscreen – ozone – in our atmosphere. This method simulates how astronomers and astrobiology researchers will search for evidence of life beyond Earth by observing potential “biosignatures” on exoplanets (planets around other stars).
    Hubble and ALMA image of MACS J1149.5+2223.

    Supernova reappearance

    On December 11, 2015, Hubble captured an image of the first-ever predicted reappearance of a supernova, dubbed “Refsdal”, which was calculated using different mass models of a galaxy cluster whose gravity is warping the supernova’s light. The supernova was previously seen in November 2014 behind galaxy cluster MACS J1149.5+2223 as part of Hubble’s Frontier Fields program. Astronomers spotted four separate images of the supernova in an arrangement known as an “Einstein Cross”.

    The light from the cluster has taken about five billion years to reach Earth, though the supernova exploded some 10 billion years ago. Based on early lens models, a fifth image was predicted to reappear by the end of 2015. The detection of Refsdal’s reappearance in December 2015 served as a unique opportunity for astronomers to test their models of how mass, especially dark matter, is distributed within this galaxy cluster.

    Impact on astronomy

    Many objective measures show the positive impact of Hubble data on astronomy. Over 15,000 papers based on Hubble data have been published in peer-reviewed journals, and countless more have appeared in conference proceedings. Looking at papers several years after their publication, about one-third of all astronomy papers have no citations, while only two percent of papers based on Hubble data have no citations. On average, a paper based on Hubble data receives about twice as many citations as papers based on non-Hubble data. Of the 200 papers published each year that receive the most citations, about 10% are based on Hubble data.

    Although the HST has clearly helped astronomical research, its financial cost has been large. A study on the relative astronomical benefits of different sizes of telescopes found that while papers based on HST data generate 15 times as many citations as a 4 m (13 ft) ground-based telescope such as the William Herschel Telescope, the HST costs about 100 times as much to build and maintain.

    Deciding between building ground- versus space-based telescopes is complex. Even before Hubble was launched, specialized ground-based techniques such as aperture masking interferometry had obtained higher-resolution optical and infrared images than Hubble would achieve, though restricted to targets about 108 times brighter than the faintest targets observed by Hubble. Since then, advances in “adaptive optics” have extended the high-resolution imaging capabilities of ground-based telescopes to the infrared imaging of faint objects.

    The usefulness of adaptive optics versus HST observations depends strongly on the particular details of the research questions being asked. In the visible bands, adaptive optics can correct only a relatively small field of view, whereas HST can conduct high-resolution optical imaging over a wide field. Only a small fraction of astronomical objects are accessible to high-resolution ground-based imaging; in contrast Hubble can perform high-resolution observations of any part of the night sky, and on objects that are extremely faint.

    Impact on aerospace engineering

    In addition to its scientific results, Hubble has also made significant contributions to aerospace engineering, in particular the performance of systems in low Earth orbit. These insights result from Hubble’s long lifetime on orbit, extensive instrumentation, and return of assemblies to the Earth where they can be studied in detail. In particular, Hubble has contributed to studies of the behavior of graphite composite structures in vacuum, optical contamination from residual gas and human servicing, radiation damage to electronics and sensors, and the long term behavior of multi-layer insulation. One lesson learned was that gyroscopes assembled using pressurized oxygen to deliver suspension fluid were prone to failure due to electric wire corrosion. Gyroscopes are now assembled using pressurized nitrogen. Another is that optical surfaces in LEO can have surprisingly long lifetimes; Hubble was only expected to last 15 years before the mirror became unusable, but after 14 years there was no measureable degradation. Finally, Hubble servicing missions, particularly those that serviced components not designed for in-space maintenance, have contributed towards the development of new tools and techniques for on-orbit repair.

    Archives

    All Hubble data is eventually made available via the Mikulski Archive for Space Telescopes at STScI, CADC and ESA/ESAC. Data is usually proprietary—available only to the principal investigator (PI) and astronomers designated by the PI—for twelve months after being taken. The PI can apply to the director of the STScI to extend or reduce the proprietary period in some circumstances.

    Observations made on Director’s Discretionary Time are exempt from the proprietary period, and are released to the public immediately. Calibration data such as flat fields and dark frames are also publicly available straight away. All data in the archive is in the FITS format, which is suitable for astronomical analysis but not for public use. The Hubble Heritage Project processes and releases to the public a small selection of the most striking images in JPEG and TIFF formats.

    Outreach activities

    It has always been important for the Space Telescope to capture the public’s imagination, given the considerable contribution of taxpayers to its construction and operational costs. After the difficult early years when the faulty mirror severely dented Hubble’s reputation with the public, the first servicing mission allowed its rehabilitation as the corrected optics produced numerous remarkable images.

    Several initiatives have helped to keep the public informed about Hubble activities. In the United States, outreach efforts are coordinated by the Space Telescope Science Institute (STScI) Office for Public Outreach, which was established in 2000 to ensure that U.S. taxpayers saw the benefits of their investment in the space telescope program. To that end, STScI operates the HubbleSite.org website. The Hubble Heritage Project, operating out of the STScI, provides the public with high-quality images of the most interesting and striking objects observed. The Heritage team is composed of amateur and professional astronomers, as well as people with backgrounds outside astronomy, and emphasizes the aesthetic nature of Hubble images. The Heritage Project is granted a small amount of time to observe objects which, for scientific reasons, may not have images taken at enough wavelengths to construct a full-color image.

    Since 1999, the leading Hubble outreach group in Europe has been the Hubble European Space Agency Information Centre (HEIC). This office was established at the Space Telescope European Coordinating Facility in Munich, Germany. HEIC’s mission is to fulfill HST outreach and education tasks for the European Space Agency. The work is centered on the production of news and photo releases that highlight interesting Hubble results and images. These are often European in origin, and so increase awareness of both ESA’s Hubble share (15%) and the contribution of European scientists to the observatory. ESA produces educational material, including a videocast series called Hubblecast designed to share world-class scientific news with the public.

    The Hubble Space Telescope has won two Space Achievement Awards from the Space Foundation, for its outreach activities, in 2001 and 2010.

    A replica of the Hubble Space Telescope is on the courthouse lawn in Marshfield, Missouri, the hometown of namesake Edwin P. Hubble.

    Major Instrumentation

    Hubble WFPC2 no longer in service.

    Wide Field Camera 3 [WFC3]

    Advanced Camera for Surveys [ACS]

    Cosmic Origins Spectrograph [COS]

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

    ESA50 Logo large

     
  • richardmitnick 9:48 am on May 4, 2021 Permalink | Reply
    Tags: "Physicists Just Found The Lightest Known Form of Uranium And It Has Unique Behaviors", , , , , Science Alert (AU)   

    From Heavy Ion Research Facility in Lanzhou China at Chinese Academy of Sciences [中国科学院] (CN) via Science Alert (AU) : “Physicists Just Found The Lightest Known Form of Uranium And It Has Unique Behaviors” 

    From Chinese Academy of Sciences [中国科学院] (CN)

    via

    ScienceAlert

    Science Alert (AU)

    4 MAY 2021
    MARA JOHNSON-GROH

    1
    Credit: IncrediVFX/iStock/Getty Images.

    Scientists have discovered a new type of uranium that is the lightest ever known. The discovery could reveal more about a weird alpha particle that gets ejected from certain radioactive elements as they decay.

    The newfound uranium, called uranium-214, is an isotope, or a variant of the element, with 30 more neutrons than protons, one fewer neutron than the next-lightest known uranium isotope.

    2
    Credit: APS/Carin Cain

    Because neutrons have mass, uranium-214 is much lighter than more common uranium isotopes, including uranium-235, which is used in nuclear reactors and has 51 extra neutrons.

    This newfound isotope isn’t just lighter than others, but it also showed unique behaviors during its decay. As such, the new findings will help scientists better understand a radioactive decay process known as alpha decay, in which an atomic nucleus loses a group of two protons and two neutrons – collectively called an alpha particle.

    Though scientists know that alpha decay results in the ejection of this alpha particle, after a century of study, they still don’t know the exact details of how the alpha particle is formed before it gets ejected.

    The researchers created the new uranium isotope at the Heavy Ion Research Facility in Lanzhou, China. There, they shone a beam of argon at a target made of tungsten inside a machine called a gas-filled recoil separator – in this case the Spectrometer for Heavy Atoms and Nuclear Structure, or SHANS. By shining a laser at the tungsten, the researchers effectively added protons and neutrons to the material to create uranium.

    The new uranium-214 isotope had a half-life of just half a millisecond, meaning that’s the amount of time it takes for half of the radioactive sample to decay. The most common isotope of uranium – called uranium-238 – has a half-life of about 4.5 billion years, which is about the age of Earth.

    By carefully watching how the isotopes decayed, the scientists were able to study the strong nuclear force – one of the four fundamental forces that hold matter together – acting on the alpha particle parts – the neutrons and protons – on the surface of the uranium.

    They found that the proton and neutron in each alpha particle interacted much more strongly than in isotopes and other elements with similar numbers of protons and neutrons that have been previously studied.

    This is likely due to the specific number of neutrons inside the nucleus of uranium-214, the researchers said. The new isotope has 122 neutrons, nearing the “magic neutron number” of 126, which is especially stable due to the configuration of the neutrons in complete sets, or shells.

    With this configuration, it is easier for scientists to calculate the strong force interaction between the protons and neutrons. That makes these isotopes particularly interesting to scientists, since studying these interactions can reveal features related to nuclear structure and decay process, said study lead author Zhiyuan Zhang, physicist at the Chinese Academy of Sciences [中国科学院](CN).

    The scientists suspect that this proton-neutron interaction could be even stronger heavier radioactive elements such as isotopes of plutonium and neptunium. These elements have a few more protons, and the configuration of their orbits suggests they could have even stronger interactions than the uranium isotopes.

    The scientists would like to study other elemental isotopes near the magic neutron number; however, since such elements have even shorter half-lives, even more sensitive detectors and more powerful beams will be needed.

    The new findings were published April 14 in the journal Physical Review Letters.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Chinese Academy of Sciences [中国科学院] (CN) is the linchpin of China’s drive to explore and harness high technology and the natural sciences for the benefit of China and the world. Comprising a comprehensive research and development network, a merit-based learned society and a system of higher education, CAS brings together scientists and engineers from China and around the world to address both theoretical and applied problems using world-class scientific and management approaches.

    Since its founding, CAS has fulfilled multiple roles — as a national team and a locomotive driving national technological innovation, a pioneer in supporting nationwide S&T development, a think tank delivering S&T advice and a community for training young S&T talent.

    Now, as it responds to a nationwide call to put innovation at the heart of China’s development, CAS has further defined its development strategy by emphasizing greater reliance on democratic management, openness and talent in the promotion of innovative research. With the adoption of its Innovation 2020 programme in 2011, the academy has committed to delivering breakthrough science and technology, higher caliber talent and superior scientific advice. As part of the programme, CAS has also requested that each of its institutes define its “strategic niche” — based on an overall analysis of the scientific progress and trends in their own fields both in China and abroad — in order to deploy resources more efficiently and innovate more collectively.

    As it builds on its proud record, CAS aims for a bright future as one of the world’s top S&T research and development organizations.

     
  • richardmitnick 1:56 pm on April 29, 2021 Permalink | Reply
    Tags: "A Massive Study of Nearly Every Glacier on Earth Just Revealed a Devastating Trend", , , , National Oceanic and Atmospheric Administration(US), Science Alert (AU)   

    From National Oceanic and Atmospheric Administration(US) via Science Alert (AU) : “A Massive Study of Nearly Every Glacier on Earth Just Revealed a Devastating Trend” 

    From National Oceanic and Atmospheric Administration(US)

    via

    ScienceAlert

    Science Alert (AU)

    29 APRIL 2021
    NICOLETTA LANESE

    1
    Chapman glacier in Canada. (National Aeronautics Space Agency (US)/ METI Ministry of Economy, Trade and Industry [経済産業省] (JP)/Japan Advanced Institute of Science and Technology (JP)/Japan Space Systems [財団法人無人宇宙実験システム研究開発機構] (JP), and US/Japan Advanced Institute of Science and Technology [北陸先端科学技術大学院大学] (JP)Team)

    Earth’s glaciers are shrinking, and in the past 20 years, the rate of shrinkage has steadily sped up, according to a new study of nearly every glacier on the planet.

    Glaciers mostly lose mass through ice melt, but they also shrink due to other processes, such as sublimation, where water evaporates directly from the ice, and calving, where large chunks of ice break off the edge of a glacier, according to the National Oceanic and Atmospheric Administration (NOAA) (US).

    By tracking how quickly glaciers are shrinking, scientists can better predict how quickly sea levels may rise, particularly as climate change drives up average global temperatures.

    But estimating the rate of glacier shrinkage can be notoriously difficult; past estimates relied on field studies of only a few hundred glaciers out of the more than 200,000 on Earth, as well as sparse satellite data with limited resolution, the authors noted in their new study, published Wednesday (April 28) in the journal Nature.

    Some of this satellite data captured changes in surface elevation, but only sampled a few places and at sparse time points.

    Other satellites detected slight shifts in the Earth’s gravitational field, but could not disentangle how much glacier shrinkage contributed to these shifts, as opposed to mass changes in ice sheets or solid earth, for instance.


    Animation: How a Glacier Melts.

    To zero in on a more precise estimate, the team used myriad satellite and aerial images to survey 217,175 glaciers, accounting for nearly all of Earth’s glaciers.

    In particular, a 20-year archive of images from NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), a high-resolution sensor aboard the Terra satellite, supplied the team with a wealth of data and allowed them to make more certain estimates of glacier mass loss through time.

    “We not only have the complete spatial coverage of all glaciers, but also repeat temporal sampling,” meaning measurements taken from many points in time, said first author Romain Hugonnet, a doctoral student at the University of Toulouse [Université de Toulouse] (FR) and the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at Swiss Federal Institute of Technology ETH Zürich [Eidgenössische Technische Hochschule Zürich)](CH) .

    The team found that, between 2000 and 2019, glaciers collectively lost an average of 293.7 billion tons (267 billion metric tonnes) of mass per year, give or take 17.6 billion tons (16 billion metric tonnes); this accounts for about 21 percent of the observed sea-level rise in that time frame, the authors noted.

    3
    Regional and global mass change rates with time series of mean surface elevation change rates for glaciers. (Hugonnet et al., Nature, 2021.)

    And for each decade since 2000, the overall rate of glacier mass loss has been accelerating, increasing by about 52.8 billion tons (48 billion metric tonnes) per year, which may account for an observed acceleration in sea-level rise.

    These estimates significantly narrow the uncertainty around how much mass glaciers lost in recent decades, Hugonnet said.

    For instance, the latest report from the Intergovernmental Panel on Climate Change (IPCC) and a recent global study, published in 2019 in the journal Nature, both calculated mass loss estimates in the same ballpark as the new study; but their margins of error spanned several hundred gigatonnes on either side.

    Hugonnet and his team were able to greatly reduce this uncertainty by using the ASTER data.

    ASTER captures images on the visible and near-infrared spectrum, “so almost what we see with our own eyes,” Hugonnet said.

    Because the sensor orbits Earth about 438 miles (750 kilometers) above the planet’s surface, it can snap images of the same locations from multiple angles: once as it passes directly over a spot and once as if it’s “looking back” from where it came.

    The two snapshots can then be used to reconstruct the 3D topography of Earth’s surface, and in this case, the 3D structure of glaciers across the planet. Hugonnet and his team quantified these changes in volume and then multiplied that by the density of glacier ice, to determine how much mass the glaciers had lost.

    The group also double-checked their work against data from NASA’s Ice, Cloud, and land Elevation Satellite (ICESat) and Operation IceBridge campaigns, a NASA project in which a fleet of research aircraft surveys Earth’s polar ice.

    This additional data confirmed that the ASTER images generally matched up with other available data front the same time period, and it also helped the team correct for statistical “noise” in the ASTER data.

    Using these methods, the team calculated a fairly confident estimate, but some uncertainty still remains, Hugonnet said.

    “The problem with glaciers is that we’re not only losing ice, we’re also losing firn,” a kind of partially compacted snow usually found on top of glaciers, he said. The current study didn’t differentiate firn from ice when estimating mass loss, “so it’s, right now, our largest source of uncertainty,” in terms of nailing down a precise rate, Hugonnet said.

    In addition, the team noted that not all Earth’s glaciers lost mass at the same rates. “What was even more interesting, and a bit surprising, was to see that some regions decelerated and others accelerated,” Hugonnet said.

    For instance, mass loss from glaciers in Alaska and western Canada ramped up significantly in the study time frame, while loss from Icelandic, Scandinavian and southeast Greenland glaciers slowed between the early 2000s and late 2010s.

    Zooming in on these regions, the authors found that regional climate conditions, specifically long-term fluctuations in precipitation and temperature, helped explain these stark differences.

    So while Iceland, Scandinavia and Greenland entered a decade of relatively cool, wet conditions in the second decade of the 21st century, northwestern North America entered a relatively dry period, meaning glaciers ultimately lost more ice than they gained snow.

    “We have those fluctuations that exist in some regions and can last for about a decade, sometimes,” Hugonnet said.

    “This is also why we need such globally complete sets of observations, such as the one we provided,” he noted.

    Tracking average glacier mass loss, on a global scale, can help scientists predict global sea-level rise; but on a local scale, glacier mass loss can drastically alter nearby bodies of water and the availability of water resources, as well as threaten to trigger disasters, such as avalanches and devastating spring floods, Hugonnet said.

    So it’s important to capture both the big picture and fine details.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    National Oceanic and Atmospheric Administration (US) is an agency that enriches life through science. Our reach goes from the surface of the sun to the depths of the ocean floor as we work to keep the public informed of the changing environment around them.

    From daily weather forecasts, severe storm warnings, and climate monitoring to fisheries management, coastal restoration and supporting marine commerce, NOAA’s products and services support economic vitality and affect more than one-third of America’s gross domestic product. NOAA’s dedicated scientists use cutting-edge research and high-tech instrumentation to provide citizens, planners, emergency managers and other decision makers with reliable information they need when they need it

     
  • richardmitnick 12:58 pm on April 29, 2021 Permalink | Reply
    Tags: "Astronomers Detect Another Mysterious Ghostly Circle in Extragalactic Space", Almost bang in the center of the ORC the team found something: an elliptical radio galaxy named DES J010224.33-245039.5., , Australian Square Kilometre Array, , , Odd radio circles - ORCs - were only discovered last year in 2019 observations collected by the Australian Square Kilometre Array Pathfinder (ASKAP)., , Science Alert (AU), The discovery of a giant ghostly circle in extragalactic space is bringing us closer to understanding what these mysterious structures actually are., The so-called odd radio circle named ORC J0102-2450,   

    From Western Sydney University (AU) via Science Alert (AU) : “Astronomers Detect Another Mysterious Ghostly Circle in Extragalactic Space” 

    From Western Sydney University (AU)

    via

    ScienceAlert

    Science Alert (AU)

    29 APRIL 2021
    MICHELLE STARR

    1
    ORC J0102-2450, as seen with SKA ASKAP and overlaid onto other surveys. (Koribalski et al., arXiv, 2021)

    The discovery of a giant ghostly circle in extragalactic space is bringing us closer to understanding what these mysterious structures actually are.

    The so-called odd radio circle named ORC J0102-2450, joins just a handful of previously discovered space blobs. Given the low sample size, the new discovery adds important statistical data that suggest these objects could somehow be related to galaxies. The paper has been accepted into MNRAS Letters.

    Humanity has been staring up and wondering about the sky for tens of thousands of years, but even so, space retains many secrets. Odd radio circles – ORCs – were only discovered last year in 2019 observations collected by the Australian Square Kilometre Array Pathfinder (ASKAP), one of the world’s most sensitive radio telescopes.

    As the name suggests, they’re apparently giant circles of relatively faint light in radio wavelengths, appearing brighter around the edges, like bubbles. Although circular objects are relatively common in space, the ORCs seemed to correspond with no known phenomenon.

    Follow-up observations with a different telescope array confirmed the presence of two of the original three ORCs, while a fourth was soon found in data collected by yet another instrument. So, we can be pretty confident these aren’t the result of some ASKAP glitch or artifact, or a phenomenon local to the telescope (like the Murriyang microwave oven) either.

    We don’t know how far away the ORCs are, which makes their size hard to gauge, but finding more of them could give us more clues. That’s where ORC J0102-2450 enters the picture.

    ASKAP conducted a series of radio continuum observations between 2019 and December 2020. To find the ORC, a team led by astronomer Bärbel Koribalski of CSIRO-Commonwealth Scientific and Industrial Research Organisation (AU) and Western Sydney University in Australia combined eight of the radio continuum images, a process that reveals objects too faint to be seen in just one or two images.

    From the combined data, a faint ring emerged. Comparison with observations from other surveys revealed no radiation in other wavelengths than radio, which can help rule out some sources of the emission.

    Interestingly, however, almost bang in the center of the ORC the team found something: an elliptical radio galaxy named DES J010224.33-245039.5.

    Sure, this could be a coincidence – but two of the other four ORCs described last year also had an elliptical radio galaxy bang in the middle. The probability of finding a radio source randomly coincident with the center of an ORC is one in a couple of hundred, the researchers said – never mind finding three of the things.

    This suggests that the circles may have something to do with elliptical radio galaxies. We know that radio galaxies often have radio lobes, huge elliptical structures that only emit in radio wavelengths ballooning out on either side of the galactic nucleus. One possibility is that the ORCs are these lobes viewed end-on, so that they appear circular.

    The ORCs could also, the researchers noted, be the product of a giant blast wave from the central galaxy, but it would have to be truly giant, produced by something like the merger of two supermassive black holes.

    If either of these scenarios is the case, the link with the galaxy can help us work out the size of the ORC. In the case of ORC J0102-2450, we know the distance to DES J010224.33-245039.5. That distance gives us a rough size estimate for ORC J0102-2450 of around 980,000 light-years. If this size is confirmed, it could help us to learn more about radio lobes or blast waves.

    The third possibility the researchers considered is an interaction between a radio galaxy and the intergalactic medium, possibly involving DES J010224.33-245039.5, although this seemed relatively unlikely to be able to produce the observed ring, the team noted.

    Although the sample size is still extremely small, and we can’t tell anything for sure just yet, the discovery of ORC J0102-2450 points to some promising directions for future observation and analysis.

    If we can find even more ORCs, they should be able to help astronomers determine how common they are, and find more similarities between them that could further narrow down their potential formation mechanisms.

    Low-frequency radio observations and X-ray observations will be of particular interest, they noted.

    “The discovery of further ORCs in the rapidly growing amount of wide-field radio continuum data from ASKAP and other telescopes will show if the above scenarios have any merit, contributing to exciting times in astronomy,” the team wrote in their paper.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Western Sydney University (AU) , formerly the University of Western Sydney, is an Australian multi-campus university in the Greater Western region of Sydney, Australia. The university in its current form was founded in 1989 under the terms of the State Legislature “Western Sydney University Act 1997 No 116”, which created a federated network university with an amalgamation between the Nepean College of Advanced Education and the Hawkesbury Agricultural College. The Macarthur Institute of Higher Education was incorporated in the university in 1989. In 2001, the University of Western Sydney was restructured as a single multi-campus university rather than as a federation. In 2015, the university underwent a rebranding which resulted in a change in name from the University of Western Sydney to Western Sydney University. It is a provider of undergraduate, postgraduate, and higher research degrees with campuses in Bankstown, Blacktown, Campbelltown, Hawkesbury, Liverpool, Parramatta, and Penrith.

    In 2021, the QS World University Rankings ranks the university 474th in the world, coming 26th in Australia and 5th in Sydney. In 2021, it was ranked in the top 300 in the world and 18th in Australia in the Times Higher Education World University Rankings.

     
  • richardmitnick 8:47 am on April 28, 2021 Permalink | Reply
    Tags: "Mysteriously Slow Pulses From Giant Old Stars May Finally Have an Explanation", , , , , Science Alert (AU), The red giant star Betelgeuse,   

    From University of Warsaw [Uniwersytet Warszawski] (PL) via Science Alert (AU) : “Mysteriously Slow Pulses From Giant Old Stars May Finally Have an Explanation” 

    From University of Warsaw [Uniwersytet Warszawski] (PL)

    via

    ScienceAlert

    Science Alert (AU)

    28 APRIL 2021
    MICHELLE STARR

    1
    Artist’s impression of an exoplanet trailing a cloud of dust. Credit: Maciej Szyszko.

    The extremely slow, steady pulsations of light from many red giant stars may finally have an explanation.

    According to a new analysis, these mysterious fluctuations in brightness are not caused by internal processes after all, but by binary companions obscured in clouds of dust siphoned off the dying giants.

    When stars of intermediate mass below around eight times the mass of the Sun reach the twilight of their lives, they go through some pretty dramatic changes.

    When they have fused all the hydrogen in their cores to helium, the nuclear fusion within ceases, and the core starts to contract. This brings more hydrogen into the region immediately around the core, forming a hydrogen shell; then, fusion starts up again, dumping helium into the core. This is called hydrogen shell burning.

    During this time, the outer layers of the star expand – by a lot. When this eventually happens to the Sun, for example, it will expand out past the orbit of Earth. This is the red giant branch of stellar evolution.

    Red giant stars often fluctuate in brightness a little, over regular periods. The red giant star Betelgeuse is a perfect example of this.

    It has several brightness cycles, including one that occurs over around 425 days, and another over around 185 days. These are caused by acoustic waves bouncing around inside the star as it expands, contracts, and expands again.

    The longest of its cycles is more mysterious. It’s what we call a “long secondary period”, and it’s 5.9 years long. Not all giant branch stars have long secondary periods, but a lot of them do – scientists have detected a long secondary period in around a third of all known giant branch stars – and these periods cannot be explained in the same way.

    A few explanations have been put forward for these mysterious thrums in the light of dying stars, including a different kind of internal oscillation, magnetic activity, or the presence of a binary companion.

    To try and get to the bottom of the mystery, a team of astronomers led by Igor Soszyński of the University of Warsaw [Uniwersytet Warszawski] (PL) conducted a close study of red giant stars with long secondary periods. From available survey data, they collated optical and mid-infrared observations of 16,000 of these stars, from which they extracted around 700 stars with a well-defined infrared light curve – a plot of the way the light changes over time – for a closer analysis.

    When comparing the optical and infrared light curves for these 700 stars, something curious emerged. In both light curves for all the stars, there was a large dip, as expected, corresponding to the stars’ dimmer periods. But for around half of the stars, there was a second, shallower dip only in the infrared light curve, exactly opposite the primary dip.

    This, the team said, is an important clue. Mid-infrared light is often produced by dust – it absorbs starlight, and re-emits it at longer wavelengths.

    This can neatly explain what’s happening around the red giant stars. If the star is being orbited by a smaller companion that has siphoned off material from the star and is therefore trailing a long dust cloud, this companion will produce a long, strong dip in starlight at all wavelengths when it passes between us and the star.

    Then, as this dusty object moves around to the side of the star, we will be able to see mid-infrared light as the starlight is absorbed and re-emitted. This mid-infrared light will dip when the binary companion moves behind the star, only to glow again when the companion re-emerges out the other side.

    According to the team’s analysis, the amplitudes of the light curves suggest that the companion is either a very low mass star, or a brown dwarf. But brown dwarfs – stars that didn’t grow large enough to be stars, but grew too large to be planets – are relatively rare.

    If the companions are brown dwarfs, the team said, they could have started their lives as smaller exoplanets, and siphoned material off the red giant stars’ outer envelopes. This suggests that most red giants with long secondary periods are orbited by objects that used to be exoplanets.

    In turn, the researchers said, this finding could allow long secondary period giant branch stars to be used as tracers for studying the planetary population of the Milky Way.

    The team’s research has been published in The Astrophysical Journal Letters.

    See the full article here.

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Warsaw [Uniwersytet Warszawski] (PL), established in 1816, is the largest university in Poland. It employs over 6,000 staff including over 3,100 academic educators. It provides graduate courses for 53,000 students (on top of over 9,200 postgraduate and doctoral candidates). The University offers some 37 different fields of study, 18 faculties and over 100 specializations in Humanities, technical as well as Natural Sciences.

    It was founded as a Royal University on 19 November 1816, when the Partitions of Poland separated Warsaw from the oldest and most influential University of Kraków. Alexander I granted permission for the establishment of five faculties – law and political science, medicine, philosophy, theology and the humanities. The university expanded rapidly but was closed during November Uprising in 1830. It was reopened in 1857 as the Warsaw Academy of Medicine, which was now based in the nearby Staszic Palace with only medical and pharmaceutical faculties. All Polish-language campuses were closed in 1869 after the failed January Uprising, but the university managed to train 3,000 students, many of whom were important part of the Polish intelligentsia; meanwhile the Main Building was reopened for training military personnel. The university was resurrected during the First World War and the number of students reached 4,500 in 1918. After Poland’s independence the new government focused on improving the university, and in the early 1930s it became the country’s largest. New faculties were established and the curriculum was extended. Following the Second World War and the devastation of Warsaw, the University successfully reopened in 1945.

    Today, University of Warsaw [Uniwersytet Warszawski] (PL) consists of 126 buildings and educational complexes with over 18 faculties: biology, chemistry, journalism and political science, philosophy and sociology, physics, geography and regional studies, geology, history, applied linguistics and Slavic philology, economics, philology, pedagogy, Polish language, law and public administration, psychology, applied social sciences, management and mathematics, computer science and mechanics.

    The University of Warsaw [Uniwersytet Warszawski] (PL) is one of the top Polish universities. It was ranked by Perspektywy magazine as best Polish university in 2010, 2011, 2014 and 2016. International rankings such as ARWU and University Web Ranking rank the university as the best Polish higher level institution. On the list of 100 best European universities compiled by University Web Ranking, the University of Warsaw [Uniwersytet Warszawski] (PL) was placed as 61st. QS World University Rankings previously positioned the University of Warsaw [Uniwersytet Warszawski] (PL) as the best higher level institution among the world’s top 400.

     
  • richardmitnick 9:29 am on April 26, 2021 Permalink | Reply
    Tags: "Climate Change Has Now Invisibly Shifted Earth's Axis New Data Reveal", , , Institute of Geographic Sciences and Natural Resources Research-Chinese Academy of Sciences [中国科学院](CN), Science Alert (AU)   

    From Institute of Geographic Sciences and Natural Resources Research-Chinese Academy of Sciences [中国科学院](CN) via Science Alert (AU) : “Climate Change Has Now Invisibly Shifted Earth’s Axis New Data Reveal” 

    From Chinese Academy of Sciences [中国科学院] (CN)

    From Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences [中国科学院](CN)

    via

    ScienceAlert

    Science Alert (AU)

    26 APRIL 2021
    PETER DOCKRILL

    1
    Credit: den-belitsky/Getty Images.

    Humanity’s impacts on our planet’s climate are so profound, we have for decades been unwittingly shifting the very axis upon which Earth spins around, scientists say.

    In a new study, researchers examined the phenomenon of polar wandering, in which Earth’s magnetic north and south poles drift around the surface of the planet, restlessly roaming from the anchored positions of their geographic counterparts.

    This mysterious phenomenon is thought to be driven by many factors, including the existence of vast anomalies of molten iron under Earth’s surface. But other elements also contribute, scientists say – including, amazingly enough, the effects of anthropogenic (human-caused) climate change.

    “Faster ice melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s,” explains [AGU-Advanced Earth and Space Science] lead researcher Shanshan Deng from the Institute of Geographic Sciences and Natural Resources Research in China.

    2
    1990s turning point: Melting of glaciers in Alaska, Greenland, the Southern Andes, Antarctica, the Caucasus and the Middle East accelerated in the mid-90s, becoming the main driver pushing Earth’s poles into a sudden and rapid drift toward 26°E at a rate of 3.28 millimeters (0.129 inches) per year.
    Color intensity on the map shows where changes in water stored on land (mostly as ice) had the strongest effect on the movement of the poles from April 2004 to June 2020. Inset graphs plot the change in glacier mass (black) and the calculated change in water on land (blue) in the regions of largest influence.
    Credit: Deng et al (2021) Geophysical Research Letters/AGU.

    In the new study [Geophysical Research Letters], Deng and fellow researchers examined the extent to which changes in terrestrial water storage (TWS) in recent decades contributed to the amount of magnetic polar wander recorded in the same timeframe.

    Basically, TWS includes changes in water levels on Earth resulting from glaciers melting as the world gets warmer, in addition to changes also produced by the pumping of groundwater from underground reservoirs.

    The reason these changes are important is because they affect the distribution of mass on Earth, and when you’re dealing with a spinning object – whether a spinning top, a yo-yo, or an entire planet revolving in space – the way its mass is distributed in turn affects the way it spins.

    “It brings an interesting piece of evidence to this question,” explains climate scientist Vincent Humphrey from the University of Zürich [Universität Zürich ] (CH), who wasn’t involved with the study.

    “It tells you how strong this mass change is – it’s so big that it can change the axis of the Earth.”

    While polar drift is a natural phenomenon that has been observed by scientists for over a century, the wandering has rapidly picked up speed in more recent times, along with a directional change from westwards to eastwards in the magnetic north pole first seen in the 1990s.

    Over time, the drifting adds up, with the poles traveling hundreds of kilometers, meaning adjustments have to be made to the World Magnetic Model, which underpins navigation systems such as GPS.

    According to the team’s calculations – based on satellite data from NASA’s Gravity Recovery and Climate Experiment(NASA Grace Mission (US)) mission and estimates of glacier loss and groundwater pumping going back to the 1980s – the primary driver of polar drift change seen in the 1990s was ice melt due to climate change.

    “The faster ice melting under global warming was the most likely cause of the directional change of the polar drift in the 1990s,” the researchers explain in their study.

    “The other possible causes are TWS change in non‐glacial regions due to climate change and unsustainable consumption of groundwater for irrigation and other anthropogenic activities.”

    While the degree of axis shift experienced so far is estimated to be so slight that humans wouldn’t be able to perceive it in daily life, the results nonetheless suggest another alarming side effect of humanity’s unsustainable usage of Earth’s resources: planetary-scale mass rearrangements significant enough to measurably affect the revolutions of the world we live upon.

    Another question is how much ongoing, locked-in ice melting – and continued plundering of groundwater resources – might impact future axis shifting, and what ramifications could result from that. We’ll have to wait and see.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Chinese Academy of Sciences [中国科学院] (CN) is the linchpin of China’s drive to explore and harness high technology and the natural sciences for the benefit of China and the world. Comprising a comprehensive research and development network, a merit-based learned society and a system of higher education, CAS brings together scientists and engineers from China and around the world to address both theoretical and applied problems using world-class scientific and management approaches.

    Since its founding, CAS has fulfilled multiple roles — as a national team and a locomotive driving national technological innovation, a pioneer in supporting nationwide S&T development, a think tank delivering S&T advice and a community for training young S&T talent.

    Now, as it responds to a nationwide call to put innovation at the heart of China’s development, CAS has further defined its development strategy by emphasizing greater reliance on democratic management, openness and talent in the promotion of innovative research. With the adoption of its Innovation 2020 programme in 2011, the academy has committed to delivering breakthrough science and technology, higher caliber talent and superior scientific advice. As part of the programme, CAS has also requested that each of its institutes define its “strategic niche” — based on an overall analysis of the scientific progress and trends in their own fields both in China and abroad — in order to deploy resources more efficiently and innovate more collectively.

    As it builds on its proud record, CAS aims for a bright future as one of the world’s top S&T research and development organizations.

     
  • richardmitnick 8:30 am on April 26, 2021 Permalink | Reply
    Tags: "The Speed of Ocean Currents Is Changing in a Major Way Scientists Warn", , , , , Science Alert (AU)   

    From Australian National University (AU) via Science Alert (AU) : “The Speed of Ocean Currents Is Changing in a Major Way Scientists Warn” 

    ANU Australian National University Bloc

    From Australian National University (AU)

    via

    ScienceAlert

    Science Alert (AU)

    1
    (National Aeronautics Space Agency (US)/Goddard Space Flight Center (US) Scientific Visualization Studio)

    26 APRIL 2021
    NAVID CONSTANTINOU ET AL.

    Scientists already know the oceans are rapidly warming and sea levels are rising. But that’s not all. Now, thanks to satellite observations, we have three decades’ worth of data on how the speeds of ocean surface currents are also changing over time.

    In research published on 23 April in the journal Nature Climate Change we detail our findings on how ocean currents have become more energetic over large parts of the ocean.

    What are ocean eddies?

    If you looked down at the ocean from a bird’s eye view, you would see some mesmerizing circular motions in the water. These features are called “ocean eddies”. They give the ocean an artistic flavor, reminiscent of Van Gogh’s Starry Night.

    1
    Van Gogh’s Starry Night. (1889)

    Eddies span somewhere between 10 and 100 kilometers (6 and 60 miles) across. They’re found all over the oceans. Certain regions, however, are particularly rich in eddies.

    These include the Gulf Stream in the North Atlantic, the Kuroshio Current in the North Pacific, the Southern Ocean which surrounds Antarctica and, closer to Australia, the East Australian Current — made famous by the film Finding Nemo.

    Ocean eddies are an integral part of ocean circulation. They move warm and cold waters from one location to others. They mix heat, carbon, salt and nutrients, and affect ocean conditions both regionally and globally.


    Gulf Stream Sea Surface Currents and Temperatures. SciTechDaily.

    Satellites constantly watch the ocean

    One way we monitor movement on the ocean’s surface is by using specialized, powerful satellites orbiting Earth. Although these satellites are thousands of kilometers above us, they can detect even just a few centimeters of change in the sea’s surface elevation.

    Then, through data analysis, we can take the change in sea surface elevation and translate it into ocean flow speeds. This can then tell us how “energetic” an ocean eddy is.

    By carefully analyzing satellite observations, our team discovered clear changes in the distribution and strength of ocean eddies. And these changes have never been detected before.

    How eddies have been changing

    Using available data from 1993 until 2020, we analyzed changes in the strength of eddies across the globe. We found regions already rich in eddies are getting even richer! And on average, eddies are becoming up to 5 percent more energetic each decade.

    One of the regions we found with the biggest change is the Southern Ocean, where a massive 5 percent increase per decade was detected in eddy activity. The Southern Ocean is known to be a hotspot for ocean heat uptake and carbon storage.

    Until recently, scientists could only observe changes in ocean eddies by using either sparse ocean measurements or the limited satellite record. The satellite record has only just become long enough for experts to draw robust conclusions about the likely longer-term trends of eddy behavior.


    Changing ocean mesoscale currents. Credit: josuena’at

    Why is this important?

    Ocean eddies play a profound role in the climate by regulating the mixing and transport of heat, carbon, biota and nutrients in the oceans. Thus, our research may have far-reaching implications for future climate.

    Scientists have known for decades that eddies in the Southern Ocean affect the overturning circulation of the ocean. As such, changes of the magnitude observed for eddies could impact the rate at which the ocean draws down heat and carbon.

    But eddies are often not taken into account in climate predictions of a warming world. Since they are relatively small, they remain practically “invisible” in current models used to project future climate.

    The impact of eddies is therefore either not resolved in climate projections, or is severely underestimated. This is particularly concerning in light of our discovery eddies are becoming more energetic.

    Our research emphasizes how crucial it is to incorporate ocean eddies into future climate projections. If we don’t, we could be overlooking a critical detail.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ANU Campus

    Australian National University (AU) is a world-leading university in Australia’s capital city, Canberra. Our location points to our unique history, ties to the Australian Government and special standing as a resource for the Australian people.

    Our focus on research as an asset, and an approach to education, ensures our graduates are in demand the world-over for their abilities to understand, and apply vision and creativity to addressing complex contemporary challenges.

    Australian National University (AU) is regarded as one of the world’s leading research universities, and is ranked as the number one university in Australia and the Southern Hemisphere by the 2021 QS World University Rankings. It is ranked 31st in the world by the 2021 QS World University Rankings, and 59th in the world (third in Australia) by the 2021 Times Higher Education.

    In the 2020 Times Higher Education Global Employability University Ranking, an annual ranking of university graduates’ employability, Australian National University (AU) was ranked 15th in the world (first in Australia). According to the 2020 QS World University by Subject, the university was also ranked among the top 10 in the world for Anthropology, Earth and Marine Sciences, Geography, Geology, Philosophy, Politics, and Sociology.

    Established in 1946, ANU is the only university to have been created by the Parliament of Australia. It traces its origins to Canberra University College, which was established in 1929 and was integrated into Australian National University (AU) in 1960. Australian National University (AU) enrolls 10,052 undergraduate and 10,840 postgraduate students and employs 3,753 staff. The university’s endowment stood at A$1.8 billion as of 2018.

    Australian National University (AU) counts six Nobel laureates and 49 Rhodes scholars among its faculty and alumni. The university has educated two prime ministers, 30 current Australian ambassadors and more than a dozen current heads of government departments of Australia. The latest releases of ANU’s scholarly publications are held through ANU Press online.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: