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  • richardmitnick 1:53 pm on December 16, 2018 Permalink | Reply
    Tags: , , , , Laniakea supercluster, , ,   

    From EarthSky: “What is the Local Group?” 

    1

    From EarthSky

    How many galaxies are now known to lie within our Local Group of galaxies? How does our Milky Way rank, size-wise? And what about the vast superclusters beyond?

    1
    One view of the Local Group- a bit to constricted.The 3 largest galaxies in the Local Group are, in descending order, Messier 31 the Andromeda galaxy, the Milky Way, and Messier 33 also known as the Triangulum Galaxy

    Iconic view of the Local Group. Andrew Z. Colvin 3 March 2011

    We know where our galaxy is located, but only locally speaking. The Milky Way galaxy is one of more than 54 galaxies known as the Local Group. The three largest members of the group are our Milky Way (second-biggest), the Andromeda galaxy (biggest) and the Triangulum Galaxy. The other galaxies in the Local Group are dwarf galaxies, and they’re mostly clustered around the three larger galaxies.

    The Local Group does have a gravitational center. It’s somewhere between the Milky Way and the Andromeda Galaxy.

    The Local Group has a diameter of about 10 million light-years.

    Astronomers have also discovered that our Local Group is on the outskirts of a giant supercluster of galaxies, known as the Virgo Supercluster.

    Virgo Supercluster NASA

    Virgo Supercluster, NASA, Wikipedia

    At least 100 galaxy groups and clusters are located within the Virgo Supercluster. Its diameter is thought to be about 110 million light-years.

    The Virgo Supercluster may be part of an even-larger structure that astronomers call the Laniakea Supercluster.

    Laniakea supercluster. From Nature The Laniakea supercluster of galaxies R. Brent Tully, Hélène Courtois, Yehuda Hoffman & Daniel Pomarède at http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html. Milky Way is the red dot.

    It consists of perhaps 100,000 galaxies stretched out over some 520 million light-years.

    See the full article here .


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    Please help promote STEM in your local schools.

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    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

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  • richardmitnick 1:21 pm on December 16, 2018 Permalink | Reply
    Tags: Huge previously-undetected coral reef off US East Coast, ,   

    From The Conversation: “Deepwater corals thrive at the bottom of the ocean, but can’t escape human impacts” 

    Conversation
    From The Conversation

    December 3, 2018
    Sandra Brooke

    When people think of coral reefs, they typically picture warm, clear waters with brightly colored corals and fishes. But other corals live in deep, dark, cold waters, often far from shore in remote locations. These varieties are just as ecologically important as their shallow water counterparts. They also are just as vulnerable to human activities like fishing and energy production.

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    Deep sea corals off Florida. Image via NOAA.

    Earlier this year I was part of a research expedition conducted by the Deep Search project, which is studying little-known deep-sea ecosystems off the southeast U.S. coast. We were exploring areas that had been mapped and surveyed by the U.S. National Oceanic and Atmospheric Administration’s research ship Okeanos.

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    Map of target areas to be surveyed during the first phase of the Deepwater Atlantic Habitats II study, DEEP SEARCH, including seep targets. USGS image.

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    NOAA Ship Okeanos Explorer

    NOAA Ship Okeanos Explorer is the only federal vessel dedicated to exploring our largely unknown ocean for the purpose of discovery and the advancement of knowledge about the deep ocean. The ship is operated by the NOAA Commissioned Officer Corps and civilians as part of NOAA’s fleet managed by NOAA’s Office of Marine and Aviation Operations. Mission equipment is operated by NOAA’s Office of Ocean Exploration and Research in partnership with the Global Foundation for Ocean Exploration .

    Missions of the 224-foot vessel include mapping, site characterization, reconnaissance, advancing technology, education, and outreach—all focused on understanding, managing, and protecting our ocean. Expeditions are planned collaboratively, with input from partners and stakeholders, and with the goal of providing data that will benefit NOAA, the scientific community, and the public.

    During Okeanos Explorer expeditions, data are collected using a variety of advanced technologies to explore and characterize unknown or poorly known deepwater ocean areas, features, and phenomena at depths ranging from 250 to 6,000 meters (820 to 19,700 feet). The ship is equipped with four different types of mapping sonars that collect high-resolution data about the seafloor and the water column, a dual-body remotely operated vehicle (ROV) capable of diving to depths of 6,000 meters, and a suite of other instruments to help characterize the deep ocean. Expeditions typically consist of either 24-hour mapping operations or a combination of daytime ROV dives and overnight mapping operations.

    In an area 160 miles off South Carolina we deployed Alvin, a three-person research submersible, to explore some features revealed during the mapping.

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    Human Occupied Vehicle (HOV) Alvin is part of the National Deep Submergence Facility (NDSF). Alvin enables in-situ data collection and observation by two scientists to depths reaching 4,500 meters, during dives lasting up to ten hours.

    What the scientists aboard Alvin found was a huge “forest” of coldwater corals. I went down on the second dive in this area and saw another dense coral ecosystem. These were just two features in a series that covered about 85 miles, in water nearly 2,000 feet deep. This unexpected find shows how much we still have to learn about life on the ocean floor.


    Scientists from the August 2018 Deep Search expedition discuss the significance of finding a huge, previously undetected deepwater coral reef off the U.S. East Coast.

    Life in the dark

    Deep corals are found in all of the world’s oceans. They grow in rocky habitats on the seafloor as it slopes down into the deep oceans, on seamounts (underwater mountains), and in submarine canyons. Most are found at depths greater than 650 feet (200 meters), but where surface waters are very cold, they can grow at much shallower depths.

    Shallow corals get much of their energy from sunlight that filters down into the water. Like plants on land, tiny algae that live within the corals’ polyps use sunlight to make energy, which they transfer to the coral polyps. Deep-sea species grow below the sunlit zone, so they feed on organic material and zooplankton, delivered to them by strong currents.

    In both deep and shallow waters, stony corals – which create hard skeletons – are the reef builders, while others such as soft corals add to reef diversity. Just five deep-sea stony coral species create reefs like the one we found in August.

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    Stylaster californicus at 135 feet depth on Farnsworth Bank off southern California. NOAA

    The most widely distributed and well-studied is Lophelia pertusa, a branching stony coral that begins life as a tiny larva, settles on hard substrate and grows into a bushy colony.

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    Lophelia pertusa

    As the colony grows, its outside branches block the flow of water that delivers food and oxygen to inner branches and washes away waste. Without flow, the inner branches die and weaken, then break apart, and the outer live branches overgrow the dead skeleton.

    This sequence of growth, death, collapse, and overgrowth continues for thousands of years, creating reefs that can be hundreds of feet tall. These massive, complex structures provide habitat for diverse and abundant assemblages of invertebrates and fishes, some of which are economically valuable.

    Other important types include gorgonians and black corals, often called “tree corals.” These species can grow very large and form dense “coral gardens” in rocky, current-swept areas. Small invertebrates and fishes use their branches for shelter, feeding and nursery habitat.

    Probing the deep oceans

    Organisms that live in deep, cold waters grow slowly, mature late and have long lifespans. Deep-sea black corals are among the oldest animals on earth: One specimen has been dated at 4,265 years old. As they grow, corals incorporate ocean elements into their skeletons. This makes them archives of ocean conditions that long predate human records. They also can provide valuable insights into the likely effects of future changes in the oceans.

    To protect these ecosystems, scientists need to find them. This is challenging because most of the seafloor has not been mapped. Once they have maps, researchers know where to deploy underwater vehicles so they can begin to understand how these ecosystems function.

    Scientists use submersibles like Alvin or remotely operated vehicles to study deep-water corals because other gear, such as trawls and dredges, would become entangled in these fragile colonies and damage them. Submersibles can take visual surveys and collect samples without impacting reefs.

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    The NOAA ROV Deep Discoverer documents benthic communities at Paganini Seamount in the north-central Pacific. NOAA

    This work is expensive and logistically challenging. It requires large ships to transport and launch the submersibles, and can only be done when seas are calm enough to work.

    Looming threats

    The greatest threat to deep corals globally is industrial bottom-trawl fishing, which can devastate deep reefs. Trawling is indiscriminate, sweeping up unwanted animals – including corals – as “bycatch.”“ It also stirs up sediment, which clogs deep-sea organisms’ feeding and breathing structures. Other forms of fishing, including traps, bottom longlines and dredges, can also impact the seafloor.

    Offshore energy production creates other problems. Oil and gas operations can release drilling muds and stir up sediments. Anchors and cables can directly damage reefs, and oil spills can have long-term impacts on coral health. Studies have shown that exposure to oil from the 2010 Deepwater Horizon spill caused stress and tissue damage in Gulf of Mexico deep-sea corals.

    Yet another growing concern is deep sea mining for materials such as cobalt, which is used to build batteries for cell phones and electric cars. The International Seabed Authority, a United Nations agency, is working with scientists and non-government organizations to develop a global regulatory code for deep sea mining, which is expected to be completed in 2020 or 2021. However, the International Union for the Conservation of Nature has warned that not enough is known about deep sea life to ensure that the code will protect it effectively.

    Finally, deep-sea corals are not immune to climate change. Ocean currents circulate around the planet, transporting warm surface waters into the deep sea. Warming temperatures could drive corals deeper, but deep waters are naturally higher in carbon dioxide than surface waters. As their waters become more acidified, deep-sea corals will be restricted to an increasingly narrow band of optimal conditions.

    Conservation and management

    Vast areas of deep coral habitats are on the high seas and are extremely difficult to manage. However, many countries have taken measures to protect deep corals within their territorial waters. For example, the United States has created several deep coral protected areas. And the U.S. Bureau of Ocean Energy Management restricts industry activities near deep corals and funds deep sea coral research.

    These are useful steps, but nations can only protect what they know about. Without exploration, no one would have known about the coral zone that we found off South Carolina, along one of the busiest coastlines in the United States. As a scientist, I believe it is imperative to explore and understand our deep ocean resources so we can preserve them into the future.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Conversation US launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
    Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.
    Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

     
  • richardmitnick 3:03 pm on December 15, 2018 Permalink | Reply
    Tags: , , , , , ,   

    From NASA Science: “NASA’s Juno Mission Halfway to Jupiter Science” 

    From NASA Science

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

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

    JoAnna Wendel
    NASA Headquarters, Washington
    202-358-1003
    joanna.r.wendel@nasa.gov

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

    1
    A south tropical disturbance has just passed Jupiter’s iconic Great Red Spot and is captured stealing threads of orange haze from the Great Red Spot in this series of color-enhanced images from NASA’s Juno spacecraft. From left to right, this sequence of images was taken between 2:57 a.m. and 3:36 a.m. PDT (5:57 a.m. and 6:36 a.m. EDT) on April 1, 2018, as the spacecraft performed its 12th close flyby of Jupiter. Citizen scientists Gerald Eichstädt and Seán Doran created this image using data from the spacecraft’s JunoCam imager. Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt/Seán Doran

    On Dec. 21, at 8:49:48 a.m. PST (11:49:48 a.m. EST) NASA’s Juno spacecraft will be 3,140 miles (5,053 kilometers) above Jupiter’s cloud tops and hurtling by at a healthy clip of 128,802 mph (207,287 kilometers per hour). This will be the 16th science pass of the gas giant and will mark the solar-powered spacecraft’s halfway point in data collection during its prime mission.

    Juno is in a highly-elliptical 53-day orbit around Jupiter. Each orbit includes a close passage over the planet’s cloud deck, where it flies a ground track that extends from Jupiter’s north pole to its south pole.

    “With our 16th science flyby, we will have complete global coverage of Jupiter, albeit at coarse resolution, with polar passes separated by 22.5 degrees of longitude,” said Jack Connerney, Juno deputy principal investigator from the Space Research Corporation in Annapolis, Maryland. “Over the second half of our prime mission — science flybys 17 through 32 — we will split the difference, flying exactly halfway between each previous orbit. This will provide coverage of the planet every 11.25 degrees of longitude, providing a more detailed picture of what makes the whole of Jupiter tick.”

    Launched on Aug. 5, 2011, from Cape Canaveral, Florida, the spacecraft entered orbit around Jupiter on July 4, 2016. Its science collection began in earnest on the Aug. 27, 2016, flyby. During these flybys, Juno’s suite of sensitive science instruments probes beneath the planet’s obscuring cloud cover and studies Jupiter’s auroras to learn more about the planet’s origins, interior structure, atmosphere and magnetosphere

    “We have already rewritten the textbooks on how Jupiter’s atmosphere works, and on the complexity and asymmetry of its magnetic field,” said Scott Bolton, principal investigator of Juno, from the Southwest Research Institute in San Antonio. “The second half should provide the detail that we can use to refine our understanding of the depth of Jupiter’s zonal winds, the generation of its magnetic field, and the structure and evolution of its interior.”

    2
    This mosaic combines color-enhanced images taken over Jupiter’s north pole when the lighting was excellent for detecting high bands of haze. The images were taken in the final hours of Juno’s perijove 12 approach on April 1, 2018. Citizen scientists Gerald Eichstädt and John Rogers created this image using data from the spacecraft’s JunoCam imager. Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt/John Rogers

    Two instruments aboard Juno, the Stellar Reference Unit and JunoCam, have proven to be useful not only for their intended purposes, but also for science data collection. The Stellar Reference Unit (SRU) was designed to collect engineering data used for navigation and attitude determination, so the scientists were pleased to find that it has scientific uses as well.

    “We always knew the SRU had a vital engineering job to do for Juno,” said Heidi Becker, Juno’s radiation monitoring investigation lead at NASA’s Jet Propulsion Laboratory in Pasadena, California. “But after making scientific discoveries in Jupiter’s radiation belts and taking a first-of-its-kind image of Jupiter’s ring, we realized the added value of the data. There is serious scientific interest in what the SRU can tell us about Jupiter.”

    The JunoCam imager was conceived as an outreach instrument to bring the excitement and beauty of Jupiter exploration to the public.

    “While originally envisioned solely as an outreach instrument to help tell the Juno story, JunoCam has become much more than that,” said Candy Hansen, Juno co-investigator at the Planetary Science Institute in Tucson, Arizona. “Our time-lapse sequences of images over the poles allow us to study the dynamics of Jupiter’s unique circumpolar cyclones and to image high-altitude hazes. We are also using JunoCam to study the structure of the Great Red Spot and its interaction with its surroundings.”

    The SRU and JunoCam teams both now have several peer-reviewed science papers —either published or in the works — to their credit.

    NASA’s JPL manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for NASA’s Science Mission Directorate. The Italian Space Agency (ASI) contributed two instruments, a Ka-band frequency translator (KaT) and the Jovian Infrared Auroral Mapper (JIRAM). Lockheed Martin Space in Denver built the spacecraft.

    More information about Juno is available at:

    https://www.nasa.gov/juno

    https://www.missionjuno.swri.edu

    More information on Jupiter is at:

    https://www.nasa.gov/jupiter

    The public can follow the mission on Facebook and Twitter at:

    https://www.facebook.com/NASAJuno

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA leads the nation on a great journey of discovery, seeking new knowledge and understanding of our planet Earth, our Sun and solar system, and the universe out to its farthest reaches and back to its earliest moments of existence. NASA’s Science Mission Directorate (SMD) and the nation’s science community use space observatories to conduct scientific studies of the Earth from space to visit and return samples from other bodies in the solar system, and to peer out into our Galaxy and beyond. NASA’s science program seeks answers to profound questions that touch us all:

    This is NASA’s science vision: using the vantage point of space to achieve with the science community and our partners a deep scientific understanding of our planet, other planets and solar system bodies, the interplanetary environment, the Sun and its effects on the solar system, and the universe beyond. In so doing, we lay the intellectual foundation for the robotic and human expeditions of the future while meeting today’s needs for scientific information to address national concerns, such as climate change and space weather. At every step we share the journey of scientific exploration with the public and partner with others to substantially improve science, technology, engineering and mathematics (STEM) education nationwide.

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  • richardmitnick 2:31 pm on December 15, 2018 Permalink | Reply
    Tags: Expansion microscopy, Implosion fabrication, , , Team invents method to shrink objects to the nanoscale, The system produces 3-D structures one thousandth the size of the originals   

    From MIT News: “Team invents method to shrink objects to the nanoscale” 

    MIT News
    MIT Widget

    From MIT News

    December 13, 2018
    Anne Trafton

    1
    MIT engineers have devised a way to create 3-D nanoscale objects by patterning a larger structure with a laser and then shrinking it. This image shows a complex structure prior to shrinking. Image: Daniel Oran

    2
    The MIT technique, known as “implosion fabrication,” can be used to create nearly any shape imaginable. Image: Daniel Oran

    It’s not quite the Ant-Man suit, but the system produces 3-D structures one thousandth the size of the originals.

    MIT researchers have invented a way to fabricate nanoscale 3-D objects of nearly any shape. They can also pattern the objects with a variety of useful materials, including metals, quantum dots, and DNA.

    “It’s a way of putting nearly any kind of material into a 3-D pattern with nanoscale precision,” says Edward Boyden, the Y. Eva Tan Professor in Neurotechnology and an associate professor of biological engineering and of brain and cognitive sciences at MIT.

    Using the new technique, the researchers can create any shape and structure they want by patterning a polymer scaffold with a laser. After attaching other useful materials to the scaffold, they shrink it, generating structures one thousandth the volume of the original.

    These tiny structures could have applications in many fields, from optics to medicine to robotics, the researchers say. The technique uses equipment that many biology and materials science labs already have, making it widely accessible for researchers who want to try it.

    Boyden, who is also a member of MIT’s Media Lab, McGovern Institute for Brain Research, and Koch Institute for Integrative Cancer Research, is one of the senior authors of the paper, which appears in the Dec. 13 issue of Science. The other senior author is Adam Marblestone, a Media Lab research affiliate, and the paper’s lead authors are graduate students Daniel Oran and Samuel Rodriques.

    Implosion fabrication

    Existing techniques for creating nanostructures are limited in what they can accomplish. Etching patterns onto a surface with light can produce 2-D nanostructures but doesn’t work for 3-D structures. It is possible to make 3-D nanostructures by gradually adding layers on top of each other, but this process is slow and challenging. And, while methods exist that can directly 3-D print nanoscale objects, they are restricted to specialized materials like polymers and plastics, which lack the functional properties necessary for many applications. Furthermore, they can only generate self-supporting structures. (The technique can yield a solid pyramid, for example, but not a linked chain or a hollow sphere.)

    To overcome these limitations, Boyden and his students decided to adapt a technique that his lab developed a few years ago for high-resolution imaging of brain tissue. This technique, known as expansion microscopy, involves embedding tissue into a hydrogel and then expanding it, allowing for high resolution imaging with a regular microscope. Hundreds of research groups in biology and medicine are now using expansion microscopy, since it enables 3-D visualization of cells and tissues with ordinary hardware.

    By reversing this process, the researchers found that they could create large-scale objects embedded in expanded hydrogels and then shrink them to the nanoscale, an approach that they call “implosion fabrication.”

    As they did for expansion microscopy, the researchers used a very absorbent material made of polyacrylate, commonly found in diapers, as the scaffold for their nanofabrication process. The scaffold is bathed in a solution that contains molecules of fluorescein, which attach to the scaffold when they are activated by laser light.

    Using two-photon microscopy, which allows for precise targeting of points deep within a structure, the researchers attach fluorescein molecules to specific locations within the gel. The fluorescein molecules act as anchors that can bind to other types of molecules that the researchers add.

    “You attach the anchors where you want with light, and later you can attach whatever you want to the anchors,” Boyden says. “It could be a quantum dot, it could be a piece of DNA, it could be a gold nanoparticle.”

    “It’s a bit like film photography — a latent image is formed by exposing a sensitive material in a gel to light. Then, you can develop that latent image into a real image by attaching another material, silver, afterwards. In this way implosion fabrication can create all sorts of structures, including gradients, unconnected structures, and multimaterial patterns,” Oran says.

    Once the desired molecules are attached in the right locations, the researchers shrink the entire structure by adding an acid. The acid blocks the negative charges in the polyacrylate gel so that they no longer repel each other, causing the gel to contract. Using this technique, the researchers can shrink the objects 10-fold in each dimension (for an overall 1,000-fold reduction in volume). This ability to shrink not only allows for increased resolution, but also makes it possible to assemble materials in a low-density scaffold. This enables easy access for modification, and later the material becomes a dense solid when it is shrunk.

    “People have been trying to invent better equipment to make smaller nanomaterials for years, but we realized that if you just use existing systems and embed your materials in this gel, you can shrink them down to the nanoscale, without distorting the patterns,” Rodriques says.

    Currently, the researchers can create objects that are around 1 cubic millimeter, patterned with a resolution of 50 nanometers. There is a tradeoff between size and resolution: If the researchers want to make larger objects, about 1 cubic centimeter, they can achieve a resolution of about 500 nanometers. However, that resolution could be improved with further refinement of the process, the researchers say.

    Better optics

    The MIT team is now exploring potential applications for this technology, and they anticipate that some of the earliest applications might be in optics — for example, making specialized lenses that could be used to study the fundamental properties of light. This technique might also allow for the fabrication of smaller, better lenses for applications such as cell phone cameras, microscopes, or endoscopes, the researchers say. Farther in the future, the researchers say that this approach could be used to build nanoscale electronics or robots.

    “There are all kinds of things you can do with this,” Boyden says. “Democratizing nanofabrication could open up frontiers we can’t yet imagine.”

    Many research labs are already stocked with the equipment required for this kind of fabrication. “With a laser you can already find in many biology labs, you can scan a pattern, then deposit metals, semiconductors, or DNA, and then shrink it down,” Boyden says.

    The research was funded by the Kavli Dream Team Program, the HHMI-Simons Faculty Scholars Program, the Open Philanthropy Project, John Doerr, the Office of Naval Research, the National Institutes of Health, the New York Stem Cell Foundation-Robertson Award, the U.S. Army Research Office, K. Lisa Yang and Y. Eva Tan, and the MIT Media Lab.

    See the full article here .


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    Please help promote STEM in your local schools.


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    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 2:05 pm on December 15, 2018 Permalink | Reply
    Tags: , , , , NASA/ESA Hera, NELIOTA-NEO Lunar Impacts and Optical TrAnsients, ,   

    From Science Alert: “Every Few Hours a Flash of Light Comes From The Moon. Another Impact” 

    ScienceAlert

    From Science Alert

    15 DEC 2018
    MATT WILLIAMS, THE UNIVERSE TODAY

    Ever since the Apollo missions explored the lunar surface, scientists have known that the Moon’s craters are the result of a long history of meteor and asteroid impacts. But it has only been in the past few decades that we have come to understand how regular these are.

    In fact, every few hours, an impact on the lunar surface is indicated by a bright flash. These impact flashes are designed as a “transient lunar phenomena” because they are fleeting.

    Basically, this means that the flashes (while common) last for only a fraction of a second, making them very difficult to detect. For this reason, the European Space Agency (ESA) created the NEO Lunar Impacts and Optical TrAnsients (NELIOTA) project in 2015 to monitor the moon for signs of impact flashes.

    By studying them, the project hopes to learn more about the size and distribution of near-Earth objects to determine if they pose a risk to Earth.

    To be fair, this phenomena is not new to astronomers, as flashes have been reportedly seen lighting up dark sections of the Moon for at least a thousand years.

    It has only been recently, however, that scientists have had telescopes and cameras sophisticated enough to observe these events and characterize them (i.e. size, speed and frequency).

    1
    (NASA/Jennifer Harbaugh)

    Determining how often such events take place, and what they can teach us about our Near-Earth environment is the reason the ESA created NELIOTA.

    In February of 2017, the project began a 22 month-long campaign to observe the Moon using the 1.2 m telescope at the Kryoneri Observatory located in Greece. This telescope is the largest instrument on Earth ever dedicated to monitoring the Moon.

    2
    Kryoneri Observatory, Greece

    In addition, the NELIOTA system is the first to use a 1.2 m-telescope for monitoring the Moon. Traditionally, lunar monitoring programs have relied on telescopes with primary mirrors measuring 0.5 m in diameter or smaller.

    The larger mirror of the Kryoneri telescope allows the NELIOTA scientists to detect flashes two magnitudes fainter than other lunar monitoring programs.

    But even with the right instruments, detecting these flashes is no easy task. In addition to lasting for only a fraction of a second, it is also impossible to spot them on the bright side of the Moon since the sunlight reflected from the surface is much brighter.

    For this reason, these events can only be seen on the Moon’s “dark side” – i.e. between a New Moon and First Quarter and between a Last Quarter and New Moon.

    The Moon must also be above the horizon at the time and observations must be conducted using a fast-frame camera. Because of these necessary conditions, the NELIOTA project has only been able to obtain 90 hours of observation time over a 22-month period, during which time 55 lunar impact events were observed.

    From this data, scientists were able to extrapolate that an average of about 8 flashes occur every hour on the surface of the Moon.

    3
    (ESA/AFP)

    Another feature that sets the NELIOTA project apart is its two fast-frame cameras that enable lunar monitoring in the visible and near-infrared bands of the spectrum.

    This allowed the project scientists to conduct the first study ever where the temperatures of lunar impacts were calculated. Of the first ten they detected, they obtained temperature estimates ranging from about 1,300 to 2,800 °C ( 2372 to 5072 °F).

    With the extension of this observing campaign to 2021, the NELIOTA scientists hope to obtain further data that will improve impact statistics.

    In turn, this information will go a long way towards addressing the threat of Near-Earth Objects – which consist of asteroids and comets that periodically pass close to Earth (and on rare occasions, impact on the surface).

    In the past, the ESA has monitored these objects through its Space Situational Awareness (SSA) program, of which the NELTIOA project is part.

    Today, the SSA is building infrastructure in space and on the ground (such as the deployment of Flyeye telescopes across the globe) to improve our monitoring and understanding of potentially hazardous NEOs.

    ESA Flyeye telescope

    In the future, the ESA plans to transition from monitoring NEOs to developing mitigation and active planetary defense strategies.

    This includes the proposed NASA/ESA Hera mission – formerly known as the Asteroid Impact & Deflection Assessment (AIDA) – which is scheduled to launch by 2023.

    NASA ESA Hera

    In the coming decades, other measures (ranging from directed energy and ballistic missiles to solar sails) are also likely to be investigated.

    But as always, the key to protecting Earth from future impacts is the existence of effective detection and monitoring strategies. In this respect, projects like NELIOTA will prove to be invaluable.

    See the full article here .


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    Please help promote STEM in your local schools.

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  • richardmitnick 1:24 pm on December 15, 2018 Permalink | Reply
    Tags: A plasma is an electrically-charged gas, A Space Playground for the Fourth State of Matter-plasma is distinct from gas liquids and solids, , , , , , Plasma Kristall at the ISS, Plasma research in microgravity   

    From European Space Agency: “A Space Playground for the Fourth State of Matter” 

    ESA Space For Europe Banner

    From European Space Agency

    1
    Visualising the laws of physics

    13 December 2018

    A recipe to understand atomic structures:

    Mix electrically-charged gas in a sealed container with particles so small they would pass through a coffee filter.
    Perform in the weightless environment of the International Space Station.
    Adjust voltage to observe how the particles form three-dimensional crystal structures.
    Start unlocking the physics behind the atoms’ behaviour.

    This is part of the formula for Plasma Kristall, the longest-running series of experiments in the history of human spaceflight and the results of the latest campaign will return to Earth next week in the Soyuz spacecraft with ESA astronaut Alexander Gerst.

    The recipe comes from a European-Russian collaboration that has been slow-cooking since 1998. After running on parabolic flights, sounding rockets and the Mir space station, the experiment found a new home at the International Space Station in 2001.

    2
    Roscosmos astronaut Sergei Prokopyev during the installation and commissioning of the new hardware in Europe’s Columbus laboratory on the International Space Station in July 2018. Sergei carried out the fifth campaign of Plasma Kristall-4 in November 2018.

    Our world is made of atoms and molecules, but even with the most powerful microscope we cannot see them moving in liquids or solids. Running experiments in weightlessness allows researchers to gain new insights into the atoms’ interaction by using tiny plastic particles that behave like atoms.

    “Doing this research on Earth is not possible – Plasma Kristall models atomic interactions on a larger scale, making their motion visible to us,” explains Hubertus Thomas, lead scientist of this experiment at the German Aerospace Centre, DLR.

    Hubertus has followed plasma research in microgravity the experiment when the first crew arrived at the Space Station and turned it on. Recently, a problem with the valve that regulates the gas flow forced an 18-month pause. With a newly refurbished valve, Plasma Kristall-4 (or PK-4) resumed operations last month.

    Proxy atoms back to science

    A plasma is an electrically-charged gas, somewhat like lightning, that rarely occurs on Earth. It is considered to be the fourth state of matter, distinct from gas, liquids and solids.

    3
    Plasma Kristall-4
    The image shows the parabolic flight setup of PK-4 used as a test model for the International Space Station. The plasma (orange glow) is created in a U-shaped glass tube with an electric field. The microparticles trapped in the chamber are illuminated by a green laser light allowing the observation of the motion of the particles. Plasma Kristall-4 will inject microscopic dust particles into a neon and argon tube to act as atom substitutes. As they float in the charged gas, they will collect negative charges as positive ions accumulate around them. As a result, they will start to repulse each other – just like atoms do in a fluid state.
    Doing this research on Earth is not possible – the dust particles would fall with gravity and the simulated atoms would not behave realistically. This experiment is making the atomic scale visible for analysis and will help scientists to understand the interactions of atoms.

    “We excite the particles using electrical fields, a laser and changes in temperature to move them in the plasma,” says Hubertus.

    These manipulations cause the proxy atoms to interact strongly, leading to organised structures – plasma crystals. The particles in PK-4 are made of plastic and bond to each other or repulse each other just as atoms do on Earth in a fluid.

    “By adjusting the voltage across the experiment chamber we can tailor their interactions, and observe each microparticle individually and as if in slow motion,” explains Hubertus. Using PK-4, researchers across the world can follow how an object melts, how waves spread in fluids and how currents change at the atomic level.

    The latest science run covered phase transitions, microscopic motions and shear forces. Shearing forces are a very hot topic in fundamental physics. These forces push one part of a body in a specific direction, and another part in the opposite direction, as for example the pressure of air along the front of an airplane wing.

    The future of plasma

    This research is mainly textbook knowledge for future scientists and engineers. “If you had asked Einstein what his theory of relativity was for, he would never have replied that it was to build a navigation system for your mobile phone,” points out Hubertus.

    A team of scientists has already made use of the know-how gained from the technological development of this space experiment to design plasma devices for the disinfection of wounds at room temperature. This revolution in healthcare has many practical applications, from food hygiene to treatment of different kinds of skin diseases, purification of water and odour management.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 1:01 pm on December 15, 2018 Permalink | Reply
    Tags: , , , , ESA Council Meeting December 2018   

    From European Space Agency: “Update From ESA Council, December 2018 

    ESA Space For Europe Banner

    From European Space Agency

    1

    The ESA Council held its 277th meeting at the European Space Operations Centre in Darmstadt on 12 and 13 December 2018

    The Council welcomed NASA Administrator Jim Bridenstine, who presented NASA’s vision for future space exploration. Mr Bridenstine praised the long-standing cooperation between ESA and NASA over the past 40 years through more than 260 major agreements including the iconic Hubble Space Telescope.

    He strongly advocated international cooperation with ESA regarding space science, Earth science, the extension of the International Space Station operations and recognised the leading role of ESA on space safety and protection of space assets.

    Looking at the future of exploration, Mr Bridenstine invited ESA to build from the International Space Station towards the Lunar Gateway as a sustainable and reusable outpost around the Moon. He congratulated ESA for delivering in November the first European Service Module as a critical element of the Orion missions and set the horizon for future missions to Mars, including the prospect of a joint cooperation with ESA on Mars Sample Return.

    Discussions with the Member States were held in view of the conclusion of the industrial contract to be signed for the production of the first batch of Ariane 6 launchers to be launched after its maiden flight in 2020. ESA proposed a way forward to stabilise the transition until full operational capability of Ariane 6.

    After almost 40 years of outstanding collaboration with Canada, which will be celebrated next year, the ESA Council unanimously approved the renewal of the cooperation agreement between ESA and the Government of Canada for a period of 10 years.

    Finally, the Council unanimously approved the proposal of the Director General concerning the renewal of its Director team of teams covering the four pillars of the agency, namely ‘Applications’, ‘Safety and Security’, ‘Science and Exploration’, ‘Enabling and Support’ as well as ‘Administration and Industrial Policy’.

    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 European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 4:36 pm on December 14, 2018 Permalink | Reply
    Tags: , , , , , , ,   

    From Imperial College London: “Young star caught forming around another star” 

    Imperial College London
    From Imperial College London

    14 December 2018
    Hayley Dunning

    1
    A small star has been observed forming out of the dust surrounding a larger star, in a similar way to how planets are born.

    Astronomers were observing the formation of a massive young star, called MM 1a, when they discovered an unexpected object nearby.

    MM 1a is surrounded by rotating disc of gas and dust. But orbiting just beyond this disc, they discovered a faint object they called MM 1b, which they discovered was a smaller star. MM 1b is believed to have formed out of the gas and dust surrounding the larger MM 1a.

    The team of astronomers, led by the University of Leeds and including an Imperial College London researcher, have published their discovery today in the journal Astrophysical Journal Letters.

    Co-author Dr Thomas Haworth, from the Department of Physics at Imperial, helped predict what might be observed around MM 1a, and then to interpret what they actually found. He said: “It’s great when the new data surprises you, which was definitely the case here.

    “Seeing the disc itself in so much detail is exciting, but detecting a second star forming within the disc, perhaps in a similar way to how planets form, was a huge unexpected bonus. There is a lot of work ahead of us to fully understand the consequences of this new discovery.”

    An entirely different formation process

    Stars form within large clouds of gas and dust in interstellar space. When these clouds collapse under gravity, they begin to rotate faster, forming a disc around them. It is in these discs that planets can form around low mass stars like our Sun.

    Lead author Dr John Ilee, from the School of Physics and Astronomy at the University of Leeds, said: “In this case, the star and disc we have observed is so massive that, rather than witnessing a planet forming in the disc, we are seeing another star being born.”

    By measuring the amount of radiation emitted by the dust and subtle shifts in the frequency of light emitted by the gas, the researchers were able to calculate the mass of MM 1a and MM 1b.

    They found that MM 1a weighs 40 times the mass of our Sun. The smaller orbiting star MM 1b was calculated to weigh less than half the mass of our Sun.

    2
    Observation of the dust emission (green) and hot gas rotating in the disc around MM 1a (red is receding gas, blue is approaching gas). MM 1b is seen the lower left. Credit: J. D. Ilee / University of Leeds.

    Dr Ilee said: “Many older massive stars are found with nearby companions. But these ‘binary’ stars are often very equal in mass, and so likely formed together as siblings. Finding a young binary system with a mass ratio of 80:1 is very unusual, and suggests an entirely different formation process for both objects.”

    The team believe stars like MM 1b could form in the outer regions of cold, massive discs. These discs are unable to hold themselves up against the pull of their own gravity, collapsing into one or more fragments.

    The team believe their discovery is one of the first examples of a ‘fragmented’ disc to be detected around a massive young star.

    Only a million years to live

    Dr Duncan Forgan, a co-author from the Centre for Exoplanet Science at the University of St Andrews, added: “I’ve spent most of my career simulating this process to form giant planets around stars like our Sun. To actually see it forming something as large as a star is really exciting.”

    The researchers note that newly discovered young star MM 1b could also be surrounded by its own disc, which may have the potential to form planets of its own – but it will need to be quick.

    Dr Ilee added: “Stars as massive as MM 1a only live for around a million years before exploding as powerful supernovae, so while MM 1b may have the potential to form its own planetary system in the future, it won’t be around for long.”

    The astronomers made this surprising discovery by using a unique new instrument situated high in the Chilean desert – the Atacama Large Millimetre/submillimetre Array (ALMA).

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    Using the 66 individual dishes of ALMA together in a process called interferometry, the astronomers were able to simulate the power of a single telescope nearly 4km across, allowing them to image the material surrounding the young stars for the first time.

    Funders for this research include the Science and Technologies Facilities Council (UK) and the European Research Council.

    See the full article here .


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    Please help promote STEM in your local schools.

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    Imperial College London

    Imperial College London is a science-based university with an international reputation for excellence in teaching and research. Consistently rated amongst the world’s best universities, Imperial is committed to developing the next generation of researchers, scientists and academics through collaboration across disciplines. Located in the heart of London, Imperial is a multidisciplinary space for education, research, translation and commercialisation, harnessing science and innovation to tackle global challenges.

     
  • richardmitnick 4:08 pm on December 14, 2018 Permalink | Reply
    Tags: , , , , , Monitoring the changing R Aquarii   

    From ESOblog: “Monitoring the changing R Aquarii” 

    ESO 50 Large

    From ESOblog

    1

    Three generations of astronomy in the last installment of ESO’s R Aquarii week

    R Aquarii is a binary system in which the violent interaction between two stars is creating a swirling nebula and a dazzling jet of light. A team of scientists have spent three decades studying this famous and unique object with ESO telescopes to find out more about various astronomical phenomena. So far this week we have published a Picture of the Week and a Photo Release looking at different aspects of this interesting star-nebula system. We wrap up the week with a blog post from Romano Corradi, an R Aquarii expert, who tells us first-hand about why this star is so interesting to study, and how our observation methods have changed over the last thirty years.

    I am particularly interested in R Aquarii because it is a symbiotic star — two interacting stars locked in a binary system in which a hot white dwarf strips away matter from a nearby cool giant star. In the case of R Aquarii, the giant is a highly evolved pulsating star reaching the end of its life; it will soon completely shed its external gaseous envelope to become a white dwarf just like its partner.

    The mass pulled away from this giant star creates an extended complex nebula that is further shaped by the surplus material that the white dwarf occasionally ejects to create loops and arcs. An accretion disk around the white dwarf sends out a jet of hot X-ray emitting material. This is the source of the S-shaped feature visible in the main photo above, which we took using ESO’s Very Large Telescope in 2012. At a distance of 650 light-years, R Aquarii is one of the closest known symbiotic systems and offers a unique opportunity to find out more about these special stars.

    One of the most challenging aspects of astronomy is that things change extremely slowly, so it can be difficult to study the dynamical nature of systems like R Aquarii, for example how fast they expand. We can only see how systems evolve by regularly taking images of them.

    My PhD supervisor, Hugo Schwarz, began imaging and studying R Aquarii in the mid-1980s, and I joined him as a PhD student in 1991. Over the years I have continued to study the symbiotic star system, and now work on the research with my own PhD students. By combining 30 years of observations, and three generations of scientific ideas and expertise, we now have a good idea of how the system evolves. But two of the key ingredients of this project really have been patience and perseverance.

    2
    R Aquarii observed using the New Technology Telescope [see NTT below] in 1991. The white vertical line in the middle is caused by light from the red giant and bright inner nebula saturating the detector. Credit: Romano Corradi

    Our work has changed a lot during this time. When I joined 27 years ago, image processing was extremely slow and direct human interaction was needed at every stage in making observations. No real pre-existing codes for processing raw data were available for most astronomical instruments, just basic guides or “recipes”. In addition to this, in the early nineties we typically had to be physically present at a telescope to observe, but nowadays we are often able to use telescopes remotely — almost from the comfort of our own homes! Improved computing power has of course made a huge difference to us. I was lucky to appear on the “astronomy scene” when large and highly efficient CCDs became commonly available in astronomical observatories. This all combined to make our research much more efficient.

    When I arrived at ESO’s La Silla Observatory as a student, I had the chance to take advantage of the superb image quality of the recently installed New Technology Telescope (NTT). The NTT really was a step forward in measuring the fine details necessary to follow the apparent growth of nearby nebulae. Since then, we have used several telescopes for our work, mainly at ESO and at the Observatorio del Roque de los Muchachos on La Palma.

    Roque de los Muchachos Observatory is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands, at an altitude of 2,396 m (7,86

    Because R Aquarii is large and fairly close, it is relatively easy to observe the region around the central binary system out to the place where the outflow mixes with the interstellar medium. At such scales, we see the imprint of the initial “kick” of the outflow. But in order to study the central “engine”, higher spatial resolutions were needed, such as those provided by the SPHERE instrument on the VLT.

    ESO SPHERE extreme adaptive optics system and coronagraphic facility on the extreme adaptive optics system and coronagraphic facility on the VLT UT3, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level

    Now a team of scientists led by Hans Martin Schmid from ETH Zurich University has actually used SPHERE to image the innermost regions of R Aquarii in extraordinary detail — even better than can be done from space — enabling them to resolve the source of the jet to further investigate how it is launched into space. It also marks the first time that we can resolve the red giant and white dwarf in this binary system.

    3
    New VLT/SPHERE observations of R Aquarii shows the binary star itself, as well as the jets of material spewing from the stellar couple. The fantastically-detailed images allow the giant star and the white dwarf star in R Aquarii to be resolved.
    Credit: ESO/Schmid et al./NASA/ESA

    R Aquarii is not the only “large-scale structure” this research could help us understand, in fact the information could revolutionise our understanding of the formation and evolution of astrophysical jets. Using SPHERE to image R Aquarii was really a test to see how much the instrument’s new ZIMPOL camera could help with investigating all of these systems in more detail than ever before. The team found that the SPHERE images were of an incredible quality, as well as being complementary to Hubble observations.

    ESO SPHERE ZIMPOL camera schematic

    The timelapse below shows just how much R Aquarii has changed over the last 20 years. At the beginning of the video, we see an image from the Nordic Optical Telescope (NOT) taken in 1997.


    The evolution of the chaotic and fascinating binary star system R Aquarii, from 1997 to today.
    Credit: T. Liimets et al./ESO/M. Kornmesser


    Nordic Optical telescope, at Roque de los Muchachos Observatory, La Palma in the Canary Islands, Spain, Altitude 2,396 m (7,861 ft)

    This is combined with another NOT image from 2007 and a VLT image from 2012 to show how the nebula is growing over time. We can even see how different parts of the system expand with different speeds, for example the white jet grows particularly fast. It is so rare to be able to see theis kind of evolution in astronomy, and I think it’s amazing!

    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 4 lasers on Yepun


    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,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).


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

    Leiden MASCARA instrument, La Silla, located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    Leiden MASCARA cabinet at ESO Cerro la Silla located in the southern Atacama Desert 600 kilometres (370 mi) north of Santiago de Chile at an altitude of 2,400 metres (7,900 ft)

    ESO Next Generation Transit Survey at Cerro Paranel, 2,635 metres (8,645 ft) above sea level

    SPECULOOS four 1m-diameter robotic telescopes 2016 in the ESO Paranal Observatory, 2,635 metres (8,645 ft) above sea level

    ESO TAROT telescope at Paranal, 2,635 metres (8,645 ft) above sea level

    ESO ExTrA telescopes at Cerro LaSilla at an altitude of 2400 metres

     
  • richardmitnick 3:40 pm on December 14, 2018 Permalink | Reply
    Tags: Abell 2597, , , , Cosmic Fountain Powered by Giant Black Hole, ,   

    From NASA Chandra: “Cosmic Fountain Powered by Giant Black Hole” 

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    NASA/Chandra Telescope


    From NASA Chandra

    2018-12-10

    1
    Abell 2597
    Credit: X-ray: NASA/CXC/SAO/G. Tremblay et al; Radio:ALMA: ESO/NAOJ/NRAO/G.Tremblay et al, NRAO/AUI/NSF/B.Saxton; Optical: ESO/VLT

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo

    Before electrical power became available, water fountains worked by relying on gravity to channel water from a higher elevation to a lower one. This water could then be redirected to shoot out of the fountain and create a centerpiece for people to admire.

    In space, awesome gaseous fountains have been discovered in the centers of galaxy clusters. One such fountain is in the cluster Abell 2597. There, vast amounts of gas fall toward a supermassive black hole, where a combination of gravitational and electromagnetic forces sprays most of the gas away from the black hole in an ongoing cycle lasting tens of millions of years.

    Scientists used data from the Atacama Large Millimeter/submillimeter Array (ALMA), the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope (VLT) and NASA’s Chandra X-ray Observatory to find the first clear evidence for the simultaneous inward and outward flow of gas being driven by a supermassive black hole.

    ESO MUSE on the VLT on Yepun (UT4),

    Cold gas falls toward the central black hole, like water entering the pump of a fountain. Some of this infalling gas (seen in the image as ALMA data in yellow) eventually reaches the vicinity of the black hole, where the black hole’s gravity causes the gas to swirl around with ever-increasing speeds, and the gas is heated to temperatures of millions of degrees. This swirling motion also creates strong electromagnetic forces that launch high-velocity jets of particles that shoot out of the galaxy.

    These jets push away huge amounts of hot gas detected by Chandra (purple) surrounding the black hole, creating enormous cavities that expand away from the center of the cluster. The expanding cavities also lift up clumps of warm and cold gas and carry them away from the black hole, as observed in the MUSE/VLT data (red).

    Eventually this gas slows down and the gravitational pull of material in the center of the galaxy causes the gas to rain back in on the black hole, repeating the entire process.

    A substantial fraction of the three billion solar masses of gas are pumped out by this fountain and form a filamentary nebula — or cosmic “spray” — that spans the innermost 100,000 light-years of the galaxy.

    These observations agree with predictions of models describing how matter falling towards black holes can generate powerful jets. Galaxy clusters like Abell 2597, containing thousands of galaxies, hot gas, and dark matter, are some of the largest structures in the entire Universe. Abell 2597 is located about 1.1 billion light years from Earth.

    A paper by Grant Tremblay (Harvard-Smithsonian Center for Astrophysics) et al. describing these results appeared in the September 18, 2018 issue of The Astrophysical Journal.

    See the full article here .


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    Please help promote STEM in your local schools.

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    NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.

     
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