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  • richardmitnick 10:02 pm on May 26, 2017 Permalink | Reply
    Tags: Astronomy, , , , , , LHS 1140, MEarth-South telescope array at Cerro Tololo Inter-American Observatory, Planet LHS 1140b   

    From CfA: “Potentially Habitable Super-Earth is a Prime Target for Atmospheric Study” 

    Harvard Smithsonian Center for Astrophysics


    Center For Astrophysics

    April 19, 2017
    Megan Watzke
    Harvard-Smithsonian Center for Astrophysics
    +1 617-496-7998
    mwatzke@cfa.harvard.edu

    Peter Edmonds
    Harvard-Smithsonian Center for Astrophysics
    +1 617-571-7279
    pedmonds@cfa.harvard.edu

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    M. Weiss/CfA

    The study of alien worlds is entering its next phase as astronomers amass the best planets outside our Solar System to look for signs of life. A newly discovered “super-Earth” orbiting in the habitable zone of a nearby small star, has catapulted itself to the top of that list.

    “This is the most exciting exoplanet I’ve seen in the past decade,” said lead author Jason Dittmann of the Harvard-Smithsonian Center for Astrophysics (CfA). “We could hardly hope for a better target to perform one of the biggest quests in science − searching for evidence of life beyond Earth.”

    The newfound planet is described in a paper appearing in the April 20th issue of the journal Nature.

    Located just 40 light-years away, the planet was found using the transit method, in which a star dims as a planet crosses in front of it as seen from Earth.

    Planet transit. NASA/Ames

    By measuring how much light this planet blocks, the team determined that it is about 11,000 miles in diameter, or about 40 percent larger than Earth.

    The researchers have also weighed the planet to be 6.6 times the mass of Earth, showing that it is dense and likely has a rocky composition. Small, potentially habitable planets have been found in the TRAPPIST-1 system, located a similar distance from Earth, but only one of those worlds has had its density measured accurately, showing that it isn’t rocky. Therefore, some or all of the others also might not be rocky.

    Since this planet transits its star, unlike the closest world to the solar system Proxima Centauri b, it can be examined for the presence of air. As the planet moves in front of the star, the star’s light will be filtered through any atmosphere and leave an imprint. Large, next-generation telescopes will be needed to tease out these subtle signals.

    “This planet will be an excellent target for the James Webb Space Telescope when it launches in 2018, and I’m especially excited about studying it with the ground-based Giant Magellan Telescope, which is under construction,” said co-author David Charbonneau of the CfA.

    NASA/ESA/CSA Webb Telescope annotated

    Giant Magellan Telescope, to be at Las Campanas Observatory, to be built some 115 km (71 mi) north-northeast of La Serena, Chile

    The planet orbits a tiny, faint star known as LHS 1140, which is only one-fifth the size of the Sun. Since the star is so dim and cool, its habitable zone (the distance at which a planet might be warm enough to hold liquid water) is very close. This planet, designated LHS 1140 b, orbits its star every 25 days. At that distance, it receives about half as much sunlight from its star as Earth.

    Although the planet is potentially habitable now, it might have faced a hellish past. When the star was young, it would have bathed the planet in a harsh ultraviolet glare that could have stripped any water from the atmosphere, leading to a runaway greenhouse effect like we see on Venus.

    However, since the planet is larger than Earth, it might have possessed a magma ocean on its surface for millions of years. Powered by heat from naturally radioactive elements, that churning ocean of lava may have fed steam into the atmosphere long after the star calmed to its current, steady glow. This process could have replenished the planet with water, making it suitable for life as we know it.

    “Right now we’re just making educated guesses about the content of this planet’s atmosphere,” said Dittmann. “Future observations might enable us to detect the atmosphere of a potentially habitable planet for the first time. We plan to search for water, and ultimately molecular oxygen.”

    In contrast with the TRAPPIST-1 star, LHS 1140 spins slowly and does not emit much high-energy radiation, which also may help the likelihood of life on its planet.

    LHS 1140 b was discovered using the MEarth-South telescope array at Cerro Tololo Inter-American Observatory.

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    MEarth-South telescope array at Cerro Tololo Inter-American Observatory

    This collection of eight telescopes, with its companion facility MEarth-North, studies faint, red stars known as M dwarfs to locate orbiting planets using the transit method.

    In follow-up work the team was able to detect LHS 1140 wobbling as the planet orbits it, using the High Accuracy Radial velocity Planet Searcher (HARPS) installed on the European Southern Observatory’s 3.6m telescope at La Silla Observatory in Chile.

    ESO/HARPS at La Silla


    ESO 3.6m telescope & HARPS at LaSilla

    This information was combined with data from the transit method, allowing the team to make good measurements of the planet’s size, mass and density.

    The MEarth Project is supported by the National Science Foundation, the David and Lucile Packard Foundation, and the John Templeton Foundation.

    See the full article here .

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    The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

     
  • richardmitnick 9:29 pm on May 26, 2017 Permalink | Reply
    Tags: Astronomy, , , , , First Stone Ceremony for ESO's Extremely Large Telescope   

    From ESO: “First Stone Ceremony for ESO’s Extremely Large Telescope” 

    ESO 50 Large

    European Southern Observatory

    26 May 2017
    Richard Hook
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Cell: +49 151 1537 3591
    Email: rhook@eso.org

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile


    A ceremony marking the first stone of ESO’s Extremely Large Telescope (ELT) has been attended today by the President of the Republic of Chile, Michelle Bachelet Jeria. The event was held at ESO’s Paranal Observatory in northern Chile, close to the site of the future giant telescope. This milestone marked the beginning of the construction of the dome and main telescope structure of the world’s biggest optical telescope, and ushered in a new era in astronomy. The occasion also marked the connection of the observatory to the Chilean national electrical grid.

    President Bachelet was today received by Tim de Zeeuw, Director General of ESO, Roberto Tamai, the ELT Programme Manager, and Andreas Kaufer, the Director of the La Silla Paranal Observatory. Aurora Williams, Minister of Mining, Luis Felipe Céspedes, Minister of Economy, and Andrés Rebolledo, Minister of Energy, were also present. In addition, the ceremony was attended by many other distinguished international and Chilean guests from government and industry, along with ESO scientists and engineers, and local and international media representatives [1].

    Highlights of the ceremony included the sealing of a time capsule prepared by ESO. The contents include a poster of photographs of current ESO staff and a copy of the book describing the future scientific goals of the telescope. The cover of the time capsule is an engraved hexagon made of Zerodur®, a one fifth-scale model of one of the ELT’s primary mirror segments.

    In her speech, the President emphasised: “With the symbolic start of this construction work, we are building more than a telescope here: it is one of the greatest expressions of scientific and technological capabilities and of the extraordinary potential of international cooperation.”

    Tim de Zeeuw thanked the President and her Government for their continuing support of ESO in Chile and their protection of the country’s unequalled skies: “The ELT will produce discoveries that we simply cannot imagine today, and it will surely inspire numerous people around the world to think about science, technology and our place in the Universe. This will bring great benefit to the ESO Member States, to Chile, and to the rest of the world.”

    Patrick Roche, President of the ESO Council, adds: “This is a milestone in ESO’s history, the ELT will be the most powerful and ambitious telescope of its kind. We have reached this point thanks to the efforts of many people in the Member States of ESO, in Chile and elsewhere, over many years. I thank them all and am delighted to see many of them here today, celebrating on this occasion.”

    With a main mirror 39 metres in diameter, the Extremely Large Telescope (ELT) will be the largest optical/infrared telescope in the world and will take telescope engineering into new territory. It will be housed in an enormous rotating dome 85 metres in diameter — comparable in area to a football pitch [2].

    One year ago, ESO signed a contract with the ACe Consortium, consisting of Astaldi, Cimolai and the nominated sub-contractor EIE Group, for the construction of the dome and telescope structure (eso1617). This was the largest contract ever awarded by ESO and also the largest contract ever in ground-based astronomy. With the laying of the first stone, the construction of the ELT dome and telescope structure has officially begun.

    The ceremony also marked the connection of the Cerro Paranal and Cerro Armazones sites to the Chilean national electrical grid. This connection, which has been made possible thanks to the strong support of the Chilean Government, is managed by the Chilean Grupo SAESA. The new connection will reduce costs and provide greater reliability and stability, as well as reduce the observatory’s carbon footprint.

    The ELT is the latest of many ESO projects that have benefited greatly from the continuing support of the Government of the host state of Chile over more than half a century. The strong support of the Ministry of Foreign Affairs, the Ministry of Energy and the National Commission for Energy (CNE) has been vital in establishing the successful connection of the site to the power grid.

    The ELT site was donated by the Government of Chile, and is surrounded by a further large concession of land to protect the future operations of the telescope from interference of all kinds — contributing towards retaining Chile’s status as the astronomy capital of the world.

    The ELT will be the biggest “eye” ever pointed towards the sky and may revolutionise our perception of the Universe. It will tackle a wide range of scientific challenges, including probing Earth-like exoplanets for signs of life, studying the nature of dark energy and dark matter, and observing the Universe’s early stages to explore our origins. It will also raise new questions we cannot conceive of today, as well as improving life here on Earth through new technology and engineering breakthroughs.

    The ELT is targeted to see first light in 2024. The laying of the first stone marks the dawn of a new era of astronomy.
    Notes

    [1] The ceremony was moved to the Paranal Residencia from the planned site on Cerro Armazones because of very high winds.

    [2] The dome will have a total mass of around 5000 tonnes, and the telescope mounting and tube structure will have a total moving mass of more than 3000 tonnes. Both of these structures are by far the largest ever built for an optical/infrared telescope and dwarf all existing ones, making the ELT truly the world’s biggest eye on the sky.

    See the full article here .

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    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

    ESO LaSilla
    ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres

    ESO VLT
    VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    ESO Vista Telescope
    ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    ESO NTT
    ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres

    ESO VLT Survey telescope
    VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level

    ALMA Array
    ALMA on the Chajnantor plateau at 5,000 metres

    ESO E-ELT
    ESO/E-ELT to be built at Cerro Armazones at 3,060 m

    ESO APEX
    APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert

     
  • richardmitnick 9:14 pm on May 26, 2017 Permalink | Reply
    Tags: Astronomy, , , , , Newly discovered fast-growing galaxies could solve cosmic riddle – and show ancient cosmic merger   

    From Max Planck Institute for astronomy: “Newly discovered fast-growing galaxies could solve cosmic riddle – and show ancient cosmic merger” 

    1

    Max Planck Institute for Astronomy

    May 24, 2017
    Science Contact
    Decarli, Roberto
    Roberto Decarli
    Phone: (+49|0) 6221 528-368
    decarli@mpia.de

    Public Information Officer
    Markus Pössel
    Public Information Officer
    Phone:(+49|0) 6221 528-261
    pr@mpia.de

    Astronomers have discovered a new kind of galaxy in the early universe, less than a billion years after the Big Bang. These galaxies are forming stars more than a hundred times faster than our own Milky Way. The discovery could explain an earlier finding: a population of suprisingly massive galaxies at a time 1.5 billion years after the Big Bang, which would require such hyper-productive precursors to grow their hundreds of billions of stars. The observations also show what appears to be the earliest image of galaxies merging. The results, by a group of astronomers led by Roberto Decarli of the Max Planck Institute for Astronomy, have been published in the 25 May issue of the journal Nature.

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    Figure 1: Artist’s impression of a quasar and neighboring merging galaxy. The galaxies observed by Decarli and collaborators are so distant that no detailed images are possible at present. This combination of images of nearby counterparts gives an impression of how they might look in more detail.
    Image: MPIA using material from the NASA/ESA Hubble Space Telescope

    NASA/ESA Hubble Telescope

    The results described here have been published as Decarli et al., “Rapidly star-forming galaxies adjacent to quasars at z>6” in the May 25, 2017 edition of the journal Nature.

    The MPIA researchers involved are

    Roberto Decarli, Fabian Walter, Bram Venemans, Emanuele Farina, Chiara Mazzucchelli, and Hans-Walter Rix

    in collaboration with

    Eduardo Bañados (Carnegie Observatories, Pasadena), Frank Bertoldi (University of Bonn), Chris Carilli (NRAO and Cavendish Laboratory, Cambridge), Xiaohui Fan (University of Arizona), Dominik Riechers (Cornell University), Michael A. Strauss (Princeton University), Ran Wang (Peking University), and Y. Yang (Korea Astronomy and Space Science Institute).

    See the full article here .

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  • richardmitnick 8:03 pm on May 26, 2017 Permalink | Reply
    Tags: , Astronomy, , , , , The Carina Nebula   

    From AAS NOVA: ” Observations of a Windy Star” 

    AASNOVA

    American Astronomical Society

    26 May 2017
    Susanna Kohler

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    The Carina Nebula, as seen by the 1.5-m Danish telescope at ESO’s La Silla Observatory. Eta Carinae is the brightest star in the image. [ESO/IDA/Danish 1.5 m/R.Gendler, J-E. Ovaldsen, C. Thöne, and C. Feron]

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    2
    ESO LaSilla 1.5 meter Danish telescope

    4
    Eta Carinae. N. Smith / J.A. Morse (U. Colorado) et al. / NASA

    The incredibly luminous massive star Eta Carinae has long posed a challenge for astronomers to model. New observations are now in … so were our models correct?

    Dramatic Target

    The massive evolved star Eta Carinae, located ~7,500 light-years away in the constellation Carina, is the most luminous star in the Milky Way. Eta Carinae has a quite a reputation for drama: it has been very unstable in the past, exhibiting repeated eruptions that have created the spectacular Homunculus Nebula surrounding it. Its present-day wind has the highest mass-loss rate of any hot star we’ve observed.

    Picture of Stellar Wind

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    Top panel: February 2017 observations of Eta Carinae in continuum (left) and H-alpha. Middle panel: the normalized radial profile for H-alpha and continuum emission. Bottom panel: the full width at half maximum for H-alpha and continuum emission of Eta Carinae. The H-alpha is about 2.5 to 3 milliarcseconds wider than the continuum. [Adapted from Wu et al. 2017]

    In our goal to understand the late evolutionary phases of very massive stars, we’ve developed radiative-transfer models to explain the behavior of Eta Carinae. One of the most well-known models, developed by John Hillier and collaborators in 2001, describes Eta Carinae’s mass loss via stellar winds. With the right observations, this model is testable, since it predicts observable locations for different types of emission. In particular, one prediction of the Hillier et al. model is that the dense, ionized winds surrounding the star should emit in H-alpha at distances between 6 and 60 AU, with a peak around 20 AU.

    This nicely testable hypothesis is rendered less convenient by the fact that it’s hard to get resolved images of Eta Carinae’s H-alpha emission. Its distance from us — and the fact that it’s shrouded in the complex nebula it created — have thus far prevented us from resolving the H-alpha emission from this star. Now, however, a team of scientists from Steward Observatory, University of Arizona have changed this.

    Confirming the Model

    Led by Ya-Lin Wu, the team obtained diffraction-limited images of Eta Carinae using the Magellan adaptive optics system. The observations, made in both H-alpha and continuum, show that the H-alpha emitting region is significantly wider than the continuum emitting region, as predicted by the model. In fact, the measured emission implies that the H-alpha line-forming region may have a characteristic emitting radius of ~25–30 AU — in very good agreement with the Hillier et al. stellar-wind model.

    This confirmation is strong support of the physical wind parameters estimated for Eta Carinae in the model, like the mass-loss rate of 10^-3 solar masses per year. These parameters are enormously helpful as we attempt to understand the physics of strong stellar-wind mass loss and the late evolutionary phases of very massive stars.
    Citation

    Ya-Lin Wu et al 2017 ApJL 841 L7. doi:10.3847/2041-8213/aa70ed

    Related Journal Articles

    See the full article for further references complete with links.

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    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
  • richardmitnick 4:51 pm on May 26, 2017 Permalink | Reply
    Tags: Astronomy, , , , , Centauris Alpha Beta Proxima, , Dr. Greg Matloff, Near-term interstellar probe   

    From Centauri Dreams: “Near-Term Interstellar Probes: Some Gentle Suggestions” 

    Centauri Dreams

    May 26, 2017
    Paul Gilster

    When Greg Matloff’s “Solar Sail Starships: Clipper Ships of the Galaxy” appeared in JBIS in 1981, the science fictional treatments of interstellar sails I had been reading suddenly took on scientific plausibility. Later, I would read Robert Forward’s work, and realize that an interstellar community was growing in space agencies, universities and the pages of journals. Since those days, Matloff’s contributions to the field have kept coming at a prodigious rate, with valuable papers and books exploring not only how we might reach the stars but what we can do in our own Solar System to ensure a bright future for humanity. In today’s essay, Greg looks at interstellar propulsion candidates and ponders the context provided by Breakthrough Starshot, which envisions small sailcraft moving at 20 percent of the speed of light, bound for Proxima Centauri. What can we learn from the effort, and what alternatives should we consider as we ponder the conundrum of interstellar propulsion?

    Dr. Greg Matloff
    Marc Millis, Paul Gilster and their associates of the Tau Zero Foundation are to be congratulated on the recent award of a $500,000 NASA grant to investigate the prospects for a near-term interstellar probe. As one of the co-authors of The Starlight Handbook, the author of Deep-Space Probes and many interstellar related papers, a former NASA consultant in this field and an Advisor to Project Starshot, I would like to offer some gentle and very personal suggestions about how to best spend this money. Since it is unlikely that I can attend this year’s Tennessee Valley Interstellar Workshop, I have elected to submit these concepts to Centauri Dreams.

    Motivation

    The basic reason for an early interstellar endeavor is knowledge acquisition. Data acquired by a star-probe en route to its destination includes in situ measurements of the interstellar medium including ions, neutral atoms, dust grains and cosmic rays. Of particular interest to designers of eventual human-carrying star arks is measurements of the directionality of high-Z cosmic rays. If these originate from discrete sources in and beyond our galaxy rather than being omni-directional, the problem of shielding a space ark will be more readily solved.

    Another possible function of such a probe is extra-galactic astrometry. If the probe carries a telescope, the very-long baseline observations possible when pairing with solar-system instruments during interstellar cruise should yield valuable data regarding distances and kinematics of extra-galactic objects.

    During the interstellar transfer after the probe’s distance from the Sun exceeds 550 AU, the Sun’s Gravitational Focus can be applied to obtain greatly amplified images of astrophysical objects occulted by the Sun. Trajectory deviations farther along the probe’s interstellar track might indicate the presence of elusive dark matter.

    Upon arrival in the destination planetary system, investigation of planets within the target star’s habitable zone will be the highest priority. Does life evolve on any water-rich world within the liquid-water temperature range, if that world has an atmosphere? Or are special conditions such as a massive satellite a requisite?

    If living planets are commonplace, do technology and civilization naturally evolve? Because we have received no unambiguous signals from hypothetical advanced extraterrestrial civilizations and intelligent ETs are apparently rare or non-existent in our solar system, our early interstellar robots should be configured to investigate the “Eerie Silence” (as Paul Davies has dubbed it) and Fermi’s Paradox (“where is everybody?”). Do advanced ETs perhaps evolve in a non-technological direction, or do they generally self-destruct? Or do they generally elect to remain radio silent and not engage in interstellar exploration and colonization?

    Destination

    I will next consider the probable destination for a probe that we might conceivably launch in the 2050-2100 time frame. Our early probes should almost certainly be directed towards the nearest stars—the Proxima/Alpha Centauri triple star system.

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    This system, which is estimated to be about 6 billion years old, consists of two central Sun-like stars (Alpha A and Alpha B) and a red dwarf companion (Proxima). Alpha A and B orbit their common center of mass in an elliptical orbit with a period of about 80 years. At their closest (periapsis), Alpha A and Alpha B are separated by about 9 Astronomical Units. At their farthest (apoapsis), their separation is in excess of 30 AU. Each of the central Centauri suns could have planets orbiting within their habitable zones. Alpha A/B Centauri is about 4.27 light years from the Sun.

    Proxima Centauri is a bit closer at 4.24 light years from the Sun. It is quite possible (but not definite) that this star is gravitationally bound to the Alpha A/B even though its current separation from Alpha A/B is about 15,000 Astronomical Units.. During the summer of 2016, the discovery of a planet with a probable mass 30% greater than Earth orbiting Proxima Centauri within that star’s habitable zone was announced. A less-than-poetic designation for this planet is Proxima b Centauri.

    Although several research teams are investigating the possibility of habitable worlds attending Alpha A or Alpha B Centauri, the discovery of Proxima b was totally unexpected. Since the nearest star to the Sun has a probable planet orbiting within its habitable zone, it is reasonable to conclude that such worlds are very common in our galaxy.

    Achievable Interstellar Transit Duration

    Our early extrasolar probes— Pioneer 10/11, Voyager 1/2, and New Horizons— don’t really count as starships.

    NASA Pioneer 10

    NASA/Voyager 1

    NASA/New Horizons spacecraft

    Yes, they have left or will eventually leave our solar system and move freely through the Milky Way galaxy. But their propulsion systems—chemical rockets combined with giant-planet gravity assists are not effective enough for true star voyaging. Even the fastest of these would require about 70,000 years to reach Proxima/Alpha Centauri if it happened to be pointing in the right direction (which it isn’t).

    A human colony ship, often called an interstellar ark or world ship, could probably be designed using near-term technology such that it could survive a millennial journey to our nearest stellar neighbor. But such a long travel time for a robotic probe would be difficult to sell to the scientific community since most research participants would prefer to see some results within their lifetimes.

    So the Breakthrough Initiatives project Breakthrough Starshot pushes technology to its limits on numerous fronts in order to design a starcraft capable of traversing the enormous distance between the Sun and Proxima/Alpha Centauri in about 20 years.

    Everything about Starshot is enormously challenging. A hyperthin sail with dimensions up to a few meters on a side must be generated.

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    Image: Artist’s concept of the Breakthrough Starshot sail under beamed acceleration. Credit: Breakthrough Initiatives.

    It must have near perfect reflectivity, high emissivity, low areal mass thickness and very high melting point. This is necessary for it to survive a several minute exposure to a 50-100 GW laser beam without melting. By the way, it must also have enormous tensile strength in order to support the nano-payload during the acceleration process. The sail must also be configured to maintain stability within the beam.

    The laser array would likely be mounted atop a Southern Hemisphere mountain, in order to point at Alpha Centauri. Adaptive optics must be used not only to compensate for the effects of Earth’s atmosphere but to insure that the beam completely fills the sail during the acceleration process at distances measured in millions of kilometers. Also, since a single continuous wave 50-100 GW laser is somewhat beyond current capabilities, thousands of smaller lasers must be synced together to produce the beam.

    Assuming that the sail survives the acceleration process, it must possess ample on-board intelligence to perform several tasks independent of Mission Control. First, it should reorient itself to travel edge-on rather than broadside through interstellar space. This is necessary to reduce the effects of dust grain impacts. Although interstellar dust is rare in our galactic vicinity, even a single grain moving at 0.2c (60,000 kilometers per second) relative to the sail has an enormous wallop.

    But we’re not done yet. Approaching Proxima/Alpha Centauri, the sail must reorient itself once again to allow its instrument suite to survey the environment of the destination stars and to send the results towards Earth. A very tall order indeed for a ~gram-massed nano payload.

    None of the above challenges present physical impossibilities. The question is whether they can all be achieved in a single nano-spacecraft within the next few decades.

    So any NASA-funded interstellar initiative intended for possible implementation within the next few decades should not attempt to duplicate the goals of Project Starshot. Rather than a 20-year travel duration, a 100-year flight time might be more realizable in the near term. Mission planners need to realize that even this is quite a challenge. A 100-200 year travel duration might be a reasonable goal.

    Proposed Propulsion Systems

    Many propulsion systems have been proposed to enable interstellar exploration and colonization. Only a few have any hope of being feasible in the near term. Before we get to the near-term possibilities, it might be nice to review some of the more exotic suggestions.

    Space Warps, Wormholes, and Hyperdrives

    It would indeed be lovely if one of these devices emerged from the realms of science fiction and Hollywood special effects into the real world. Then we could wander the star lanes with the same dispatch that we book a flight to Europe.

    Unfortunately, all of these short-cuts through space-time require either enormous amounts of energy, exotic forms of matter or new physics. It seems wise to continue research in these possibilities. There is no telling when or if a breakthrough might occur. But it would be unwise to hold our collective breaths.

    Thrust Machines

    In the 1960’s, we were treated to the famous Dean Drive. Now engineers in several international locations are testing the Shawyer EM Drive. These and similar devices apparently violate one of the basic laws of classical mechanics: Conservation of Linear Momentum. Although excess unidirectional thrust seems to be generated by the EM Drive, Marc Millis has described in this blog numerous possible causes for this effect that do not violate this law.

    Before any proposed thrust machine can be seriously considered for application to interplanetary or interstellar propulsion, it must demonstrate excess thrust in outer space conditions. Two venues for preliminary in-space tests are stratospheric balloons and sub-orbital rockets. If these succeed, a follow-on demonstration would be a dedicated cubesat containing the device deployed in Low Earth Orbit.

    The Matter/Antimatter Rocket

    This physically possible interstellar propulsion system utilizes total conversion of matter to energy in the reaction between matter and antimatter. Sadly, we are a very long way from the capability of creating the necessary mass of antimatter in a reasonable time frame. If we applied humanity’s best antimatter factory (the Large Hadron Collider) to the the task of full-time antimatter production, we might have a gram of the stuff after 100 million years.

    Another problem is storing the antimatter. Charged sub-atomic particles can be stored in Penning Traps for periods of weeks. These devices use crossed electric and magnetic fields to contain the particles. If applied in space travel, how would the trap’s fields compensate for variable spacecraft acceleration? Also, might stray cosmic rays heat and divert the anti-ions so that they explosively interact with the walls of the containment vessel?

    Perhaps it’s a good thing that application matter-antimatter technology does not seem a near-term possibility. Our security would be jeopardized enormously (and probably terminally) if terrorists could smuggle city-killing weapons in thimble-sized containers.

    Ramjets and EM Sails

    By far the most elegant of physically possible interstellar spacecraft is Robert Bussard’s fusion ramjet. This craft utilizes an electromagnetic (EM) scoop to collect interstellar hydrogen over a large area and redirect the plasma to a proton-proton fusion reactor. Energized fusion products (helium nuclei) are exhausted out the rear of the craft. An ideal ramjet, accelerating at 1g could reach near-optic velocities in about a year Earth time. Because of relativistic effects, the craft could cross the galaxy within the crew’s lifetime, according to on-board clocks.

    Sadly, there are a few problems with the proton-fusing ramjet. First and most significant is the difficulty of igniting the proton-proton thermonuclear reaction. This reaction, which powers main sequence stars such as our Sun, is many orders of magnitude more difficult to ignite than the fusion reactions we currently experiment with. One way around this is to consider lower performance ramjet alternatives such as the ram-augmented interstellar rocket (RAIR) that carries on-board fusion fuel and uses scooped protons as additional reaction mass.

    But even that approach is limited by the limitations of EM scoops that have been suggested to date. Most (including those considered by this author) function better as proton reflectors or drag sails—very good for interstellar deceleration but not too effective for achieving high velocities. The one exception to this is Brice Cassenti’s toroidal scoop, suggested in the late 1990’s. But because this scoop utilizes an array of superconducting wires projected in front of the spacecraft, only accelerations of the order 0.01 g are possible.

    In the near future, the best we can likely hope for to apply ramjet technology is in-space experiments using electric and magnetic sails to reflect the solar wind. This might encourage the perfection of both an interplanetary propulsion option requiring no on-board fuel and experimental tests of an approach to interstellar deceleration.

    Beamed Propulsion

    It is unclear whether Project Starshot’s imaginative enterprise will be successful. Even if a beam projector is located on a high mountain, it is not known how rapidly it can be adjusted to compensate for atmospheric turbulence. Another unknown is whether the beam-steering mechanism will be efficient enough to keep the beam output directed at Alpha/Proxima Centauri for several minutes. Finally, much analysis is required to insure that the beam is centered on the sail and fills the sail during the acceleration process.

    Any funded consideration of interstellar probes would be wise, however, to investigate terrestrial and in-space experiments to demonstrate the utility of beamed propulsion. These could be far less ambitious and expensive than the Project Starshot concepts.

    For example, imagine two cubesats launched simultaneously into Low Earth Orbit. One contains a wafer sail. Its neighbor deploys a very low-power laser or maser projector. The beam is focused on the unfurled sail. It should be possible to monitor both sail acceleration and stability in the beam.

    Another possibility is to repeat an experiment originally planned for the failed Planetary Society Cosmos-1 Earth-orbiting solar-photon sail. After the sail is unfurled, a microwave beam from a terrestrial radio telescope could be focused on the sail. If sail stability and acceleration can be demonstrated, this will advance the possibility of Earth-escape by low-orbit photon sails as well as furthering the cause of interstellar travel.

    Theoretical researchers might also expand the concept of particle-beam propulsion. Because electrically charged sub-atomic particles carry significantly more linear momentum than photons, it would be interesting to develop an understanding of particle-beam collimation over interplanetary and interstellar distances.

    But there is a geopolitical obstacle to the construction of a ~gigawatt laser-, maser-, or particle-beam projector in space. Such a device could be applied to accelerating a starship or diverting an Earth-threatening asteroid; it could also be construed as a weapon.

    If such an enormous beam projector could be constructed in space and could maintain its aim for decades, a hybrid interstellar propulsion system might ultimately become feasible. This is the laser ramjet. In such a vehicle, interstellar ions collected by a Cassenti EM scoop could be accelerated by energy beamed from the solar system.

    Fission-Electric Propulsion

    Nuclear fission has been an available energy source for more than 70 years. The solar-electric rocket (or ion drive) has been used successfully on several interplanetary probes. One reasonable approach to interstellar travel is to remove the solar panels and connect the ion drive’s thruster to a nuclear-fission reactor. In such a device, the reactor energy output would ionize propellant atoms (or molecules) and accelerate the resulting ions out the rear of the spacecraft.

    There are at least three factors limiting interstellar application of fission-electric propulsion. One is propellant availability. To reduce thruster erosion, the inert gas xenon is used as propellant in most current solar-electric drives. Applying this approach to the much more massive fuel requirement of an interstellar probe would likely far exceed the annual terrestrial production rate of xenon. Alternative propellants should be investigated.

    Then there is the matter of geopolitics. Many citizens of our planet would be somewhat unnerved if one of the major space powers began to store the large amount of fissionable material required in Low Earth Orbit during construction of the massive probe. One way around this is to construct the probe as an international project, similar to that applied to creation and operation of the International Space Station.

    Technology is another limitation. Present day ion thrusters are limited to exhaust velocities of about 100 kilometers per second. So a nuclear-electric rocket launched using current technology might require 10,000 years to reach Alpha/Proxima Centauri.

    Exhaust velocity must be raised to at least 1000 kilometers/second to propel a “1000-year ark”, as discussed by Les Shepherd in his 1952-vintage JBIS paper on interstellar travel. To reduce probe flight time to 100 years or so, the ion-exhaust velocity must be increased by another order of magnitude.

    Another required improvement to implement ion-propelled interstellar travel is the reduction of the propulsion system’s specific mass (kilograms/kilowatts). As my late friend, the UK propulsion expert Dr. David Fearn once told me, such a reduction is challenging but ultimately not impossible.

    Thermonuclear Fusion Rockets

    There are two major types of fusion under development. Magnetic fusion, which confines the reacting plasma in EM fields, seems to always be a few decades in the future. Some have quipped that it is the energy source and the propulsion system of the future and always will be.

    Small scale inertial fusion confines and compresses micropellets using crossed electron or laser beams. Large scale inertial fusion—the hydrogen bomb—accomplishes confinement and heating reactants using fission charges, and has of course been operational for more than 60 years.

    Large scale inertial-fusion propulsion was first investigated during the early space age by NASA and the US Department of Defense in the original Project Orion. The first demonstration in a scientific journal of the near-term feasibility of large-scale interstellar travel was Freeman Dyson’s original paper on an interstellar Orion in the October 1968 issue of Physics Today. Assuming propulsion by exploding hydrogen bombs, Dyson demonstrated that the US and USSR Cold War nuclear arsenals were sufficient to dispatch thousands of migrants on colonization ships. The estimated duration of one-way voyages to Alpha/Proxima Centauri was 130-1,300 years.

    In an ideal world, the former Cold War adversaries would be glad to donate their now-obsolete thermonuclear arsenals to the worthy cause of promoting an interstellar diaspora. Sadly, we do not live in such a world.

    Even if nuclear “devices” would be donated to the worthy cause of interstellar exploration/colonization, there are a few technical difficulties to contend with. Unless we can master aneutronic fusion reactions such as the boron-proton scheme, it must be demonstrated that spacecraft structures can survive periodic high-energy thermal-neutron doses.

    Application of fusion micro pellets also has a number of technical issues. First, there is the problem of fuel availability. To reduce neutron irradiation on ship structures, the Daedalus study of the British Interplanetary Society (BIS) considered a Deuterium-Helium3 fusion fuel cycle. The problem is that Helium3 is very rare on Earth. To construct a Daedalus craft, cosmic helium sources must be tapped—perhaps the lunar regolith, atmospheres of giant planets or the solar wind.

    The BIS follow-up to Daedalus, called Icarus, uses a Deuterium-Tritium fuel cycle. Here, it might be necessary to breed Tritium in nuclear fission reactors.

    Some engineering issues must be addressed before Daedalus/Icarus-type pulsed fusion ships can become operational. What are the acoustic effects of repeated fusion ignitions within the reaction chamber? Will the walls of the reaction chamber be damaged if laser- or electron-beams miss a fuel pellet?

    Another significant issue is the enormous size of inertial fusion ships. Even if payload mass can be drastically reduced, the beam projectors, reaction chamber and associated gear are massive.

    One suggestion to reduce the mass of an inertial-fusion propelled spacecraft is worthy of future study. That is Johndale Solem’s Medusa concept. In Medusa, the massive reaction chamber is replaced by a hyper-thin, high-melting-point, radiation-tolerant sail. Fusion charges are ignited within this flexible canopy, which is connected to the payload by strong cables.

    The Solar-Photon Sail

    There are several reasons why photon sails have emerged as the near-term interstellar propulsion system of choice. First, small photon sails have been unfurled and operated in Earth orbit and interplanetary space.

    Second, the photon sail can be scaled with the payload. A payload-on-a-chip requires a small sail. If the payload is small enough, sail and payload can be deployed from a small cubesat. Sail deployment and integration with payload can therefore be based upon current operational experience.

    But today’s multi-layer solar-photon sails are not really capable of interstellar travel. Even if sail acceleration is combined with giant-planet gravity assists, it seems clear that Alpha/Proxima Centauri travel times less than 10,000 years will be difficult to achieve.

    The best we can expect from current solar-photon sails is exploration of the heliopause at around 550 AU, the Sun’s gravity focus at >550 AU, and the inner reaches of the Sun’s Oort Comet Cloud.

    In all likelihood, interstellar probes launched by solar-photon sails will never be as fast as those launched by laser-photon or maser-photon sails. The reason for this is that solar irradiance is an inverse square phenomenon—acceleration at Jupiter is 1/25 that at Earth’s solar orbit. A collimated and accurately aimed beam could maintain sail acceleration over much greater distances.

    But the advantage of solar-photon over beam-photon sails is that mission designers need not concern themselves with the beam-projection system. The solar constant should not vary too much for the foreseeable future.

    So a number of researchers have evaluated the possibility of all-metal sails, dielectric sails, carbon nanotube sails and mesh sails. But the ultimate sail material might be a molecular monolayer such as graphene.

    Graphene is a hyper-strong layer of carbon, one molecule thick. Its melting point is in excess of 4,000 K and it is impermeable to many gases. In the visible spectral range, graphene is essentially transparent. Its fractional visible absorption is 0.023. As I describe in a 2012 JBIS paper, combination with other materials can increase reflectivity to about 0.05 and absorption to ~0.4. Graphene sails carrying robotic payloads and unfurled near the Sun seem capable of reaching Alpha/Proxima Centauri in a few centuries. Because human-carrying arks are limited to ~3g accelerations, these larger ships require about 1,000 years to reach these stars if they are propelled by graphene sails.

    But here is where Project Starshot can play a very major role. In order to reach ~0.2c in a ~50 GW laser beam without melting, the sail reflectivity to laser light must be very high. Perhaps this can be achieved with an appropriate mesh-like meta material. Or perhaps the reflectivity of molecular monolayers such as graphene can be greatly increased.

    After the Project Starshot workshop last August, participants produced draft Requests For Proposals (RFPs). I have discussed the possibility of increasing graphene reflectivity with theoretical condensed-matter researchers at my home institution (CUNY). It is quite possible that they will submit a proposal in response to the RFP when it is issued.

    If monolayer reflectivity can be greatly increased, it will be necessary to demonstrate that this action does not adversely affect monolayer tensile strength so that the wafer sail is strong enough to support the payload during a very close solar approach. It will also be necessary to demonstrate that sail and payload can survive the very hostile environment encountered near the Sun.

    A solar-photon sail will likely never achieve the ~0.2c interstellar velocity of the laser-boosted Project Starshot sail. But, just possibly, solar-photon-sail terminal velocities capable of making the journey to Alpha/Proxima Centauri in a century or so may not be totally infeasible.

    5

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    Tracking Research into Deep Space Exploration

    Alpha Centauri and other nearby stars seem impossible destinations not just for manned missions but even for robotic probes like Cassini or Galileo. Nonetheless, serious work on propulsion, communications, long-life electronics and spacecraft autonomy continues at NASA, ESA and many other venues, some in academia, some in private industry. The goal of reaching the stars is a distant one and the work remains low-key, but fascinating ideas continue to emerge. This site will track current research. I’ll also throw in the occasional musing about the literary and cultural implications of interstellar flight. Ultimately, the challenge may be as much philosophical as technological: to reassert the value of the long haul in a time of jittery short-term thinking.

     
  • richardmitnick 3:09 pm on May 26, 2017 Permalink | Reply
    Tags: Astronomy, , , , ,   

    From COSMOS: “CubeSats: exploring other planets on a budget” 

    Cosmos Magazine bloc

    COSMOS

    26 May 2017
    Cathal O’Connell

    1
    Anthony Calvert
    Hitchhiking could be the new way to see the solar system. No towel required.
    Specifications
    Name: Mars Cube One (MarCO)
    Destination: Martian orbit
    Mission cost:
    (MarCO) US$13 million,
    (Insight) US$425 million
    Launch Date: 20 May 2018
    Mars Arrival: 26 November 2018
    Dimensions (while stowed): 36.6 x 24.3 x 4.6 x 11.8 cm.
    Mass: 14 kg

    Any man who can hitch the length and breadth of the galaxy, rough it, slum it, struggle against terrible odds, win through, and still knows where his towel is is clearly a man to be reckoned with.” – Douglas Adams

    Exploring the solar system is absurdly expensive. Even a single mission, such as NASA’s US$675 million InSight probe to Mars, scheduled to launch in May 2018, would eclipse the total science budget of most nations.

    NASA Mars Insight Lander

    But with tiny, hitchhiking satellites called CubeSats, there may finally be a way to explore other planets on a shoestring.

    Tagging along on that InSight mission will be two CubeSats – small, boxy satellites the size of a carry-on suitcase. Built by NASA’s Jet Propulsion Laboratory, these Mars Cube One (or MarCO) probes will be the first CubeSats to voyage to another planet. If they pull off their US$13 million mission – peanuts compared with any previous interplanetary mission – MarCO could lead to a shift in how we explore the solar system, even opening the doors to smaller nations to stake a claim. Space travel finally has an economy-class fare.

    CubeSats were originally designed as a training tool, so university students could design and build satellites in the timeline of a semester. The basic idea was to cram the instrumentation into a standard template: a cube with 10 cm sides.

    Almost 20 years on, more than 500 cubesats have been launched successfully into orbit, with another 600 launches planned for 2017 alone. CubeSats have turned into the great leveller of modern space exploration, achievable within the budget of schools, universities, or even crowdfunding campaigns.

    See the full article here .

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  • richardmitnick 2:33 pm on May 26, 2017 Permalink | Reply
    Tags: Astronomy, , , , , Spiral Galaxy NGC 6744   

    From Manu: “Spiral Galaxy NGC 6744” 


    Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    1

    The Spiral Galaxy NGC 6744 big, beautiful has almost a size of 175.000 light years, is bigger than our own milky way. It is located about 30 million light-years away in the southern constellation of turkey which appears as a weak object using small telescopes. We see the disc of the nearby island universe tilted to our line of sight. This remarkable, distinguished and detailed portrait of the galaxy covers an area around the angular size of the full moon. In It, the core of the yellowish giant galaxy is dominated by the lights of old stars and fresh. Beyond the nucleus, the spiral arms filled with young blue star clusters and regions of star formation rosaceae sweep beyond a satellite galaxy smaller in the bottom left, reminiscent of the satellite galaxy of the milky way, the great Magellanic Cloud.

    Image Credit & Copyright: Daniel Verschatse

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  • richardmitnick 2:25 pm on May 26, 2017 Permalink | Reply
    Tags: Astronomy, , , , ,   

    From Manu: “Eta Carinae, the prelude to a supernova” 


    Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    1

    In the early nineteenth century, the binary star system Eta Carinae was weak and undistinguished. In the first decades it became increasingly brighter until April 1843 was the second brightest star in the sky, just behind Sirius (nearly a thousand times closer to Earth). In the years that followed, gradually he eased again in the twentieth century and was completely invisible to the naked eye. Star varying in brightness has continued since then and while once again visible to the naked eye on a dark night has never come close to its peak of 1843.

    The star system Eta Carinae is a binary system is composed of two stars, the larger of the two stars is a huge and unstable star nearing the end of his life and the events observed by the astronomers of the nineteenth century was a stellar experience near death. Scientists call these outbursts supernova impostor events that appear similar to supernovae but stop just in time to destroy the star.

    Although nineteenth – century astronomers did not have telescopes powerful enough to see the outbreak of 1843 in detail, its effects can be studied today. Huge clouds of matter thrown a century and a half ago, known as the Nebula Homúncula have been a regular target for Hubble since its launch in 1990. This image, taken with the Advanced Camera for Surveys High Resolution Channel is the most detailed , however, it shows us how the star material was not ejected in a uniform manner but held as a huge dumbbell.

    Eta Carinae is not only interesting for its past, but also for its future. It is one of the closest stars to Earth is likely to explode in a supernova in the relatively near future (though in astronomical timescales the “near future” could still be a million years). When you do, wait a breathtaking view from Earth, visible only from the southern hemisphere, much brighter even than the latest outbreak observed SN 2006gy , the brightest supernova ever observed coming from a star of the same type.

    This image consists of visible and ultraviolet images of high resolution channel of Hubble’s Advanced Camera for Surveys light. The field of view is about 30 arcseconds. Eta Carinae is located at a distance of 7,500 light-years away in the constellation Carina.

    Credit:
    ESA / Hubble and NASA

    For more information here.

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  • richardmitnick 2:41 pm on May 25, 2017 Permalink | Reply
    Tags: Astronomy, , , , ,   

    NASA Ames: “NASA Selects New Research Teams to Further Solar System Exploration Research” 

    NASA Ames Icon

    March 17, 2017 [How did this slip by me?]
    Kimberly Williams
    Ames Research Center, Silicon Valley
    650-604-2457
    kimberly.k.williams@nasa.gov

    1
    No image caption or credit

    In an effort to advance basic and applied research for lunar and planetary science, and advance human exploration of the solar system through scientific discovery, NASA created the Solar System Exploration Research Virtual Institute or SSERVI. The institute fosters collaborations with science and exploration communities, which enables cross-disciplinary partnerships with research institutions, both domestic and abroad.

    NASA has selected four new research teams to join the existing nine teams in SSERVI to address scientific questions about the moon, near-Earth asteroids, the Martian moons Phobos and Deimos, and their near space environments, in cooperation with international partners.

    “We look forward to collaborative scientific discoveries from these teams,” said Jim Green, director of the Planetary Science Division of NASA’s Science Mission Directorate in Washington. “These results will be vital to NASA successfully conducting the ambitious activities of exploring the solar system with robots and humans.”

    SSERVI members include academic institutions, non-profit research institutes, private companies, NASA centers and other government laboratories. The new teams – which SSERVI will support for five years at a combined total of about $3-5 million per year – were selected from a pool of 22 proposals based on competitive peer-review evaluation.

    The selected SSERVI member teams, listed with their principal investigators and research topics, are:

    Network for Exploration and Space Science (NESS); Jack Burns, University of Colorado, Boulder, Colorado. NESS will implement cross-disciplinary partnerships to advance scientific discovery and human exploration at target destinations by conducting research in robotics, cosmology, astrophysics and heliophysics that is uniquely enabled by human and robotic exploration at the moon, near-Earth asteroids and comets, and Phobos and Deimos.

    Toolbox for Research and Exploration (TREX); Amanda Hendrix, Planetary Science Institute, Tucson, Arizona. TREX aims to develop tools and research methods for exploration of airless bodies, like the moon and asteroids, that are coated in fine-grained dust in order to prepare for human missions. Laboratory spectral measurements and experiments will accompany studies of existing datasets to understand surface characteristics and to investigate potential resources on airless bodies.

    Radiation Effects on Volatiles and Exploration of Asteroids and Lunar Surfaces (REVEALS); Thomas Orlando, Georgia Institute of Technology, Atlanta, Georgia. The REVEALS team will explore radiation processing of natural regolith and human-made composite materials to understand the condensed-matter physics and radiation chemistry that can lead to volatile formation, sequestration and transport. This team also will explore how novel materials and real-time radiation detectors can minimize risks and exposure to dangerous radiation during human exploration missions.

    Exploration Science Pathfinder Research for Enhancing Solar System Observations (ESPRESSO); Alex Parker, Southwest Research Institute, Boulder, Colorado. Team ESPRESSO will focus on characterizing target surfaces and mitigating hazards that create risk for robotic and human explorers. It will work to assess the geotechnical and thermomechanical properties of target body surfaces to help us understand and predict hazards like landslides, and to improve our understanding of impact ejecta dynamics.

    “We are extremely pleased that the community responded with such high-quality proposals, and look forward to the many contributions SSERVI will make in addressing NASA’s science and exploration goals,” said SSERVI Director Yvonne Pendleton.

    The SSERVI central office, located at NASA’s Ames Research Center in Silicon Valley, is funded by the agency’s Science Mission Directorate and Human Exploration and Operations Mission Directorate, and manages national and international collaborative partnerships, designed to push the boundaries of science and exploration.

    For more information about SSERVI and selected member teams, visit:

    http://sservi.nasa.gov

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    Ames Research Center, one of 10 NASA field Centers, is located in the heart of California’s Silicon Valley. For over 60 years, Ames has led NASA in conducting world-class research and development. With 2500 employees and an annual budget of $900 million, Ames provides NASA with advancements in:
    Entry systems: Safely delivering spacecraft to Earth & other celestial bodies
    Supercomputing: Enabling NASA’s advanced modeling and simulation
    NextGen air transportation: Transforming the way we fly
    Airborne science: Examining our own world & beyond from the sky
    Low-cost missions: Enabling high value science to low Earth orbit & the moon
    Biology & astrobiology: Understanding life on Earth — and in space
    Exoplanets: Finding worlds beyond our own
    Autonomy & robotics: Complementing humans in space
    Lunar science: Rediscovering our moon
    Human factors: Advancing human-technology interaction for NASA missions
    Wind tunnels: Testing on the ground before you take to the sky

    NASA image

     
  • richardmitnick 1:49 pm on May 25, 2017 Permalink | Reply
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    From JPL-Caltech: “A Whole New Jupiter: First Science Results from NASA’s Juno Mission” 

    NASA JPL Banner

    JPL-Caltech

    May 25, 2017

    Dwayne Brown
    Headquarters, Washington
    202-358-1726
    dwayne.c.brown@nasa.gov

    Laurie Cantillo
    Headquarters, Washington
    202-358-1077
    laura.l.cantillo@nasa.gov

    DC Agle
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-393-9011
    agle@jpl.nasa.gov

    Nancy Neal Jones
    Goddard Space Flight Center, Greenbelt, Md.
    301-286-0039
    nancy.n.jones@nasa.gov

    Deb Schmid
    Southwest Research Institute, San Antonio
    210-522-2254
    dschmid@swri.org

    1
    This image shows Jupiter’s south pole, as seen by NASA’s Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). The oval features are cyclones, up to 600 miles (1,000 kilometers) in diameter. Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection.
    Credits: NASA/JPL-Caltech/SwRI/MSSS/Betsy Asher Hall/Gervasio Robles

    3
    An image of Jupiter taken by the Juno spacecraft. Credit: J.E.P. Connerney et al., Science (2017)phys.org

    3
    Credit: J.E.P. Connerney et al., Science (2017)phys.org

    Early science results from NASA’s Juno mission to Jupiter portray the largest planet in our solar system as a complex, gigantic, turbulent world, with Earth-sized polar cyclones, plunging storm systems that travel deep into the heart of the gas giant, and a mammoth, lumpy magnetic field that may indicate it was generated closer to the planet’s surface than previously thought.

    “We are excited to share these early discoveries, which help us better understand what makes Jupiter so fascinating,” said Diane Brown, Juno program executive at NASA Headquarters in Washington. “It was a long trip to get to Jupiter, but these first results already demonstrate it was well worth the journey.”

    Juno launched on Aug. 5, 2011, entering Jupiter’s orbit on July 4, 2016. The findings from the first data-collection pass, which flew within about 2,600 miles (4,200 kilometers) of Jupiter’s swirling cloud tops on Aug. 27, are being published this week in two papers in the journal Science [http://science.sciencemag.org/cgi/doi/10.1126/science.aal2108] and [http://science.sciencemag.org/cgi/doi/10.1126/science.aam5928] , as well as 44 papers in Geophysical Research Letters [too many to chase down].

    “We knew, going in, that Jupiter would throw us some curves,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “But now that we are here we are finding that Jupiter can throw the heat, as well as knuckleballs and sliders. There is so much going on here that we didn’t expect that we have had to take a step back and begin to rethink of this as a whole new Jupiter.”

    Among the findings that challenge assumptions are those provided by Juno’s imager, JunoCam. The images show both of Jupiter’s poles are covered in Earth-sized swirling storms that are densely clustered and rubbing together.

    “We’re puzzled as to how they could be formed, how stable the configuration is, and why Jupiter’s north pole doesn’t look like the south pole,” said Bolton. “We’re questioning whether this is a dynamic system, and are we seeing just one stage, and over the next year, we’re going to watch it disappear, or is this a stable configuration and these storms are circulating around one another?”

    Another surprise comes from Juno’s Microwave Radiometer (MWR), which samples the thermal microwave radiation from Jupiter’s atmosphere, from the top of the ammonia clouds to deep within its atmosphere. The MWR data indicates that Jupiter’s iconic belts and zones are mysterious, with the belt near the equator penetrating all the way down, while the belts and zones at other latitudes seem to evolve to other structures. The data suggest the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred miles or kilometers.

    Prior to the Juno mission, it was known that Jupiter had the most intense magnetic field in the solar system. Measurements of the massive planet’s magnetosphere, from Juno’s magnetometer investigation (MAG), indicate that Jupiter’s magnetic field is even stronger than models expected, and more irregular in shape. MAG data indicates the magnetic field greatly exceeded expectations at 7.766 Gauss, about 10 times stronger than the strongest magnetic field found on Earth.

    “Juno is giving us a view of the magnetic field close to Jupiter that we’ve never had before,” said Jack Connerney, Juno deputy principal investigator and the lead for the mission’s magnetic field investigation at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Already we see that the magnetic field looks lumpy: it is stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action closer to the surface, above the layer of metallic hydrogen. Every flyby we execute gets us closer to determining where and how Jupiter’s dynamo works.”

    Juno also is designed to study the polar magnetosphere and the origin of Jupiter’s powerful auroras—its northern and southern lights. These auroral emissions are caused by particles that pick up energy, slamming into atmospheric molecules. Juno’s initial observations indicate that the process seems to work differently at Jupiter than at Earth.

    Juno is in a polar orbit around Jupiter, and the majority of each orbit is spent well away from the gas giant. But, once every 53 days, its trajectory approaches Jupiter from above its north pole, where it begins a two-hour transit (from pole to pole) flying north to south with its eight science instruments collecting data and its JunoCam public outreach camera snapping pictures. The download of six megabytes of data collected during the transit can take 1.5 days.

    “Every 53 days, we go screaming by Jupiter, get doused by a fire hose of Jovian science, and there is always something new,” said Bolton. “On our next flyby on July 11, we will fly directly over one of the most iconic features in the entire solar system — one that every school kid knows — Jupiter’s Great Red Spot. If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno and her cloud-piercing science instruments.”

    NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Juno mission for NASA. The principal investigator is Scott Bolton of the Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space Systems, in Denver, built the spacecraft.

    More information on the Juno mission is available at:

    https://www.nasa.gov/juno

    http://missionjuno.org

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    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    Caltech Logo

    NASA image

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
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