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  • richardmitnick 12:58 pm on December 5, 2019 Permalink | Reply
    Tags: "Icy Moons and Their Plumes", , , , , , , , What is not at all common is liquid water   

    From Many Worlds: “Icy Moons and Their Plumes” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    December 5, 2019
    Marc Kaufman

    1
    The existence of water or water vapor plumes on Europa has been studied for years, with a consensus view that they do indeed exist. Now NASA scientists have their best evidence so far that the moon does sporadically send water vapor into its atmosphere. (NASA/ESA/K. Retherford/SWRI)

    Just about everything that scientists see as essential for extraterrestrial life — carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur and sources of energy — is now known to be pretty common in our solar system and beyond. It’s basically there for the taking by untold potential forms of life.

    But what is not at all common is liquid water. Without liquid water Earth might well be uninhabited and today’s Mars, which was long ago significantly wetter, warmer and demonstrably habitable, is widely believed to be uninhabited because of the apparent absence of surface water (and all that deadly radiation, too.)

    This is a major reason why the discovery of regular plumes of water vapor coming out of the southern pole of Saturn’s moon Enceladus has been hailed as such a promising scientific development.

    NASA’s Solar System Exploration. Color image of icy Enceladus, the sixth-largest moon of Saturn

    The moon is pretty small, but most scientists are convinced it does have an under-ice global ocean that feeds the plume and just might support biology that could be collected during a flyby.

    But the moon of greatest scientific interest is Europa, one of the largest that orbits Jupiter.

    2
    Varied terrain on Europa. Credit: NASA/JPL-Caltech/SETI Institute

    It is now confidently described as having a sub-surface ocean below its crust of ice and — going back to science fiction writer extraordinaire Arthur C. Clarke — has often been rated the most likely body in our solar system to harbor extraterrestrial life.

    That is why it is so important that years of studying Europa for watery plumes has now paid off. While earlier observations strongly suggested that sporadic plumes of water vapor were in the atmosphere, only last month was the finding nailed, as reported in the journal Nature Astronomy.

    “While scientists have not yet detected liquid water directly, we’ve found the next best thing: water in vapor form,” said Lucas Paganini, a NASA planetary scientist who led the water detection investigation.

    3
    As this cutaway shows, vents in Europa’s icy crust could allow plumes of water vapor to escape from a sub-surface ocean. If observed up close, the chemical components of the plumes would be identified and could help explain the nature and history of the ocean below. ( NASA)

    The amount of water vapor found in the European atmosphere wasn’t great — about an Olympic-sized pool worth of H2O. Looking at the moon from the W. M. Keck Observatory in Hawaii, the scientists saw water molecules on the side of Europa that’s always facing in the direction of the moon’s orbit around Jupiter.

    Keck Observatory, operated by Caltech and the University of California, Maunakea Hawaii USA, 4,207 m (13,802 ft)

    But Paganini’s team registered the faint signal of water vapor just once throughout 17 nights of observations between 2016 and 2017

    That fact, Paganini said in a release, was significant. “For me,” he said, “the interesting thing about this work is not only the first direct detection of water above Europa, but also the lack (of more plumes found) within the limits of our detection method.”

    More advanced detection equipment certainly might find much more water in the atmosphere, and that possibility is where Europa eclipses Enceladus as the icy moon most likely to give up some of its closest kept secrets in the near term.

    Because in the next five years or so, not one but two major missions are scheduled to head for Europa — NASA’s Europa Clipper and the European Space Agency-led JUpiter ICy moons Explorer mission (JUICE.)

    NASA/Europa Clipper annotated

    ESA/Juice spacecraft depiction


    How the JUICE spacecraft will fly to the Jupiter system, using five gravity boosts along the way. (ESA)

    Although several missions have been proposed to return to Enceladus with more specialized instruments than the Cassini spacecraft had when it flew through a plumes in 2015, none have been formally approved and funded.

    NASA/ESA/ASI Cassini-Huygens Spacecraft

    JUICE is scheduled to launch first to Europa — as early as 2022. Because it will need multiple gravity boosts from other bodies to reach the Jupiter system, it is not expected to arrive before the late 2020s.

    As for the Europa Clipper, the launch date remains uncertain but estimated to be in the mid 2020s. If it can use the NASA’s super-heavy Space Launch System (SLS) for its launch, it could reach Jupiter and Europa before JUICE. But because of endless delays with the SLS development, and the desire to use its unique lift power if and when it becomes available for launches to our moon and elsewhere, the Clipper may well launch on a commercial rocket and need the same time-consuming boosts.

    The Europa Clipper and JUICE missions are different in many ways, but they do have the same Jupiter system and Europa destinations and so are in a race of sorts to be the first to taste Europa’s atmosphere up close.

    It’s a cooperative race for sure — NASA does have an instrument planned to ride on the JUICE mission — but who gets there first will be of some space-faring importance just because Europa has long been such a promising destination for scientists.

    Some Europa background:

    Forty years ago, a Voyager spacecraft snapped the first closeup images of Europa, one of Jupiter’s 79 moons.

    NASA/Voyager 2

    These revealed brownish cracks slicing the moon’s icy surface, which give Europa the look of an eyeball with criss-crossing veins. Missions to the outer solar system in the decades since have amassed enough additional information about Europa to make it a high-priority target of investigation in NASA’s search for life.

    For instance, NASA’s Galileo spacecraft, measured perturbations in Jupiter’s magnetic field near Europa while orbiting the gas giant planet.

    NASA/Galileo 1989-2003

    The measurements, taken between 1995 and 2003, suggested to scientists that electrically conductive fluid, likely a salty ocean beneath Europa’s ice layer, was causing the magnetic disturbances. When researchers analyzed the magnetic disturbances more closely in 2018, they found evidence of possible plumes.

    In the meantime, scientists announced in 2013 that they had used NASA’s Hubble Space Telescope to detect the chemical elements hydrogen (H) and oxygen (O) — components of water (H2O) — in plume-like configurations in Europa’s atmosphere. And a few years later, other scientists used Hubble to gather more evidence of possible plume eruptions when they snapped photos of finger-like projections that appeared in silhouette as the moon passed in front of Jupiter.

    Lorenz Roth, an astronomer and physicist from KTH Royal Institute of Technology in Stockholm who led the 2013 Hubble study and was a co-author of this recent investigation, said that detecting water vapor on other worlds is especially challenging.

    Existing spacecraft have limited capabilities to detect it, he said, and scientists using ground-based telescopes to look for water in deep space have to account for the distorting effect of water in Earth’s atmosphere. To minimize this effect, Paganini’s team used complex mathematical and computer modeling to simulate the conditions of Earth’s atmosphere so they could differentiate Earth’s atmospheric water from Europa’s in data returned by the Keck spectrograph.

    KECK Echellette Spectrograph and Imager (ESI)

    They used a spectrograph at the Keck Observatory that measures the chemical composition of planetary atmospheres through the infrared light they emit or absorb. Molecules such as water emit specific frequencies of infrared light as they interact with solar radiation.

    So while scientists had evidence that key ingredients for life, including liquid water, were present under Europa’s icy surface and that liquid geysers might sometimes erupt into the atmosphere, nobody had fully confirmed the presence of water in these plumes by directly measuring the water molecule itself. Until, that is, the recent confirmation by by scientists at NASA’s Goddard Space Flight Center and their international partners.

    The recent finding of a plume of water vapor in the Europan atmosphere will help scientists better understand the inner workings of the moon. Any lingering doubts have been alleviated about the presence of a liquid water ocean, possibly twice as large as Earth’s, beneath this moon’s miles-thick ice shell. And clearly and importantly, conditions in the ocean would have to be changeable, in some flux, if water is periodically pushed up to the surface and into the atmosphere.

    There are, of course, other theories of the source of the Europa plumes. Another is that that the water and vapor comes from shallow reservoirs of melted water ice not far below Europa’s surface. It’s also possible that Jupiter’s strong radiation field is stripping water particles from Europa’s ice shell, though the recent investigation argued against this mechanism as the source of the observed water.

    As Avi Mandell, a Goddard planetary scientist on Paganini’s team, put it:. “Eventually, we’ll have to get closer to Europa to see what’s really going on.”

    So if Europa is getting all this attention, why are there no parallel big missions planned to Enceladus? After all, the plumes (or geysers) coming out of the moon are known to be consistent and substantial.

    One mission was proposed for last year’s NASA New Frontiers class competition and was well received but ultimately not selected. The German Space Agency has been studying an Enceladus mission since 2012 and Breakthrough Initiative founder Yuri Milner, a Russian billionaire living in the United States, is working with a small NASA team on an simple, relatively inexpensive spacecraft to fly again through the plume and test for organic compounds and possibly by-products of biology.

    In effect, Milner and his colleagues believe the possibility of finding life on Enceladus is scientifically too tempting to wait for a full NASA effort — which appears unlikely while the costly Europa Clipper mission is under development.

    Briefly, the Enceladus geysers — which sometimes form a curtain of vapor –erupt from the moon’s south polar region. They were first interpreted as being the result of tidally produced pressure and heat in a subterranean sea, with fissures in the ice allowing the water and water vapor to escape. More recently, an even more intriguing source of the needed heat has been proposed.

    In 2017, an article in the journal Science by J. Hunter Waite of the Southwest Research Institute et al reported that measurements taken during Cassini mission’s final fly-through captured the presence of molecular hydrogen in the plumes. To planetary and Earth scientists, that particular hydrogen presence quite clearly means that the water shooting out from Enceladus is coming from an interaction between water and warmed rock minerals at the bottom of the moon’s ocean– and possibly from within hydrothermal vents.

    These chimney-like vents at the bottom of our oceans — coupled with a chemical mixture of elements and organic compounds similar to what has been detected in the plumes — are known on Earth as prime breeding grounds for life. One important reason why is that the hydrogen and hydrogen compounds produced in these settings are a source of energy, or food, for microbes.

    A logical conclusion of these findings: the odds that Enceladus harbors forms of simple life increased with the finding, though remain impossible to quantify.

    Less is known about the composition of the apparently far more sporadic plumes of Europa, but JUICE and the Europa Clipper will — if they arrive successfully — change that. They too may find a chemical soup conducive to life, and similar signs of deep ocean interactions between the salty ocean and rock minerals heated hydrothermally, through radiation, tidal pressures or perhaps all of the above.

    And, no doubt, the precious water and water vapor in those plumes will be the gateway to their understandings.

    See the full article here .


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    Please help promote STEM in your local schools.

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    About Many Worlds
    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    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.

     
  • richardmitnick 12:15 pm on December 5, 2019 Permalink | Reply
    Tags: "These overlooked global diseases take a turn under the microscope", , , Hookworm, Leishmaniasis, , ,   

    From Penn Today: “These overlooked global diseases take a turn under the microscope” 


    From Penn Today

    December 4, 2019
    Katherine Unger Baillie, Writer
    Eric Sucar, Photographer

    1
    In rural areas of Nigeria, such as this small fishing village in the north, children are at risk of infection with hookworm as well as other parasites. De’Broski Herbert of the School of Veterinary Medicine is embarking on a study of the disease in Nigerian schoolchildren. (Image: De’Broski Herbert)

    Most people don’t die from tropical diseases like hookworm, schistosomiasis, or even malaria. But these understudied diseases, often caused by parasites, rob people of health in sometimes insidious ways.

    For example, schistosomiasis is a disease caused by a waterborne, snail-transmitted parasite, and it’s the research focus of the School of Veterinary Medicine’s Robert Greenberg.

    2
    Schistosomiasis, a disease caused by parasitic flatworms, has long been a research focus for Penn Vet’s Robert Greenberg. (Image: John Donges/Penn Vet)

    “It’s not necessarily a death sentence, though there are fatalities” says Greenberg, a research associate professor of pathobiology. “But you get anemia, children get stunted in terms of growth and cognitive abilities. It’s a disease that keeps people in poverty.”

    Such diseases, by and large, receive less financial support and, as a result, far less scientific attention than those that more often afflict residents of wealthier nations, such as diabetes and heart disease.

    Penn Vet researchers, however, have committed attention to these diseases, which, taken as a whole, affect billions around the globe. Their work benefits from the niche strengths of the school, specifically in immunology and host-pathogen interactions.

    “At the Vet School, a third of our funding supports infectious disease research,” says Phillip Scott, vice dean for research and academic resources and a professor of microbiology and immunology in the Department of Pathobiology. “That’s pretty amazing, given that the School is also awarded funding for regenerative medicine, for cancer, and for a variety of other areas.”

    That strength is seen in the research portfolios of some of the more senior faculty, such as Christopher Hunter’s work on toxoplasmosis, James “Sparky” Lok’s studies of Strongyloides, Carolina Lopez’s investigations of lung infections, and Bruce Freedman and Ron Harty’s efforts against Ebola and other hemorrhagic viral diseases. It has attracted newer faculty members, like cryptosporidium expert Boris Striepen, to Penn Vet.

    3
    Parasitology professor James Lok’s studies of the development and basic biology of parasites, particularly the roundworm
    Strongyloides, have implications for finding new drug candidates. Veterinary schools have traditionally been strongholds of parasitology research, and Penn Vet is no exception. (Image: Eric Sucar)

    Raising awareness

    Penn Vet’s De’Broski Herbert, for example, an associate professor of pathobiology, had held prior positions at Cincinnati Children’s Hospital and the University of California, San Francisco. He had felt called to work on hookworm, a parasite he first learned of growing up in the South from his great-grandmother, who warned him about walking around barefoot because of the risk of contracting the parasite. But at the medical centers where he worked, he shifted gears away from studying the parasite itself, instead focusing on related research in asthma and allergy.

    5
    As part of his hookworm research in Nigeria, Herbert (left), speaking with Babatunde Adewale of the Nigerian Institute for Medical Research, hopes to study the impacts of infection on the microbiome, the immune system, and more. (Image: Courtesy of De’Broski Herbert)

    “Here, our veterinary students are likely to encounter parasites in their patients, so working directly on the parasite is easier to justify,” Herbert says.

    This spring, Herbert traveled to Nigeria where, working with partners at the Nigerian Institute for Medical Research, he launched a study of hookworm in 300 school-aged children in five sites around the northern and central portions of the country.

    “The goal is to first establish what the prevalence of the disease really is and draw attention to that,” Herbert says. “And secondly, this is a place where the World Health Organization is going in and doing mass treatments, so I’m also interested in learning something very novel about the association between the microbiome, tissue repair, immune suppression, and metabolism in these children in Nigeria.”

    Pairing basic and translational science

    Those insights could lead to treatments, but they will also likely shed new light on the basic science of how hookworms affect their host. This pairing of basic and applied work is characteristic of Penn Vet scientists. In Scott’s lab, for instance, which has long pursued studies of the tropical disease leishmaniasis, advances in basic science have unfurled alongside insights that stand to reshape treatment of this parasitic infection which, in its cutaneous form, can cause serious and chronic skin ulcers.

    “When I was a postdoc at NIH, there’s something my boss used to say that I still use in my talks,” says Scott. “He said, ‘Leishmaniasis has done more for immunology than immunology has done for leishmaniasis.’ And you could substitute parasitology for leishmaniasis and it would be much the same quote.

    7
    The Leishmania parasite (in red), transmitted by a sandfly, can cause painful, disfiguring ulcers. Immunologist Phillip Scott and collaborators including Daniel Beiting have worked to understand the immune response to infection and better tailor treatment for those affected. (Image: Courtesy of Phillip Scott)

    “What I think is exciting right now,” he adds, “is that that’s going to change.”

    As part of this contribution toward advancements against parasitic disease, Scott has traveled regularly to a leishmaniasis clinic in Brazil to obtain samples for his research and, back at Penn, has paired up with dermatology and microbiome experts such as Elizabeth Grice in the Perelman School of Medicine, and Dan Beiting from Penn Vet’s Center for Host-Microbial Interactions to break new ground.

    No vaccine exists for leishmaniasis and current therapies fail a substantial percentage of the time. But recent publications from Scott’s lab have revealed new information about how the disease and existing treatments work and when to predict when they don’t. At the same time, Scott and colleagues’ research into the immunology of the infection has identified ways that FDA-approved drugs could be leveraged to alleviate the most severe forms of leishmaniasis.

    New diagnostics

    A major hurdle to matching appropriate therapies with neglected disease comes at one of the earliest stages of medical intervention: diagnostics. Researchers at Penn Vet are employing innovative techniques to fill these unmet needs. Robert Greenberg is one who has crossed disciplinary boundaries to do so.

    In a partnership between Greenberg and Haim Bau of Penn’s School of Engineering and Applied Science, the scientists are working to craft an improved diagnostic test for schistosomes, which can lead to schistosomiasis, causing anemia, tissue fibrosis and lesions, malnutrition, learning difficulties, and, depending on the parasite species, bladder cancer and heightened HIV risk.

    Greenberg has studied the ion channels that govern key biological functions in schistosomes to potentially develop drug targets that paralyze and kill the organisms. And by adapting insights from other researchers about additional parasitic-specific targets, he’s helping Bau train his microfluidic, portable diagnostic system on schistosomes to one day help clinicians make point-of-care diagnoses and issue timely treatment for infected patients.

    “The current diagnostics are pretty terrible,” Greenberg says. “We’re looking at some new approaches now that should give us a much earlier, more sensitive, and more specific diagnosis for individual patients that might be able to detect other coinfections simultaneously.”

    At Penn Vet’s New Bolton Center, Marie-Eve Fecteau and Ray Sweeney are also taking part in the design of a 21st-century solution to diagnostics of an insidious and challenging disease, in this case, a disease that takes a particular toll on livestock: paratuberculosis, or Johne’s disease. Caused by the bacterium Mycobacterium avium paratuberculosis, the condition affects ruminants such as cows and goats and drastically decreases their weight and milk production.

    8
    Infectious diseases take a toll on livestock as well, indirectly impacting human health and livelihoods. Large animal veterinarians Marie-Eve Fecteau and Raymond Sweeney are making progress on a stall-side diagnostic system that could quickly identify calves infected with paratuberculosis, halting the spread of infection. (Image: Louisa Shepard)

    “Ruminants are a very important part of survival and livelihood in developing countries,” says Fecteau, an associate professor of food animal medicine and surgery. “Families may rely on only one or two cows to provide for their nutritional needs or income, and if that cow is affected by Johne’s, that’s a serious problem.”

    Paratuberculosis has been shown to be endemic in parts of India and elsewhere in Asia and is also a burden for U.S. farms, where 70% of dairy herds test positive for the infection. Separating infected animals from the herd is a key step to stem the spread, but the bacteria have proved difficult to grow in the lab, making diagnosis challenging.

    Fecteau and Sweeney, the Mark Whittier & Lila Griswold Allam Professor at Penn Vet, are hoping to change that, working with Beiting and biotechnology firm Biomeme to develop a “lab in a fanny pack,” as they call it: A stall-side diagnostic test that relies on PCR to identify infected animals from stool samples within hours.

    “This is the kind of technology that could be extremely valuable for use in areas where sophisticated technology is harder to come by,” says Sweeney.

    Stopping disease where it starts

    Elsewhere at Penn Vet, researchers are approaching globally significant diseases by focusing on the vector. In the insectary that is part of Michael Povelones’s lab, he and his team test methods to stop disease-transmission cycles within mosquitoes.

    8
    The tens of thousands of mosquitoes in Michael Povelones’s insectary enable new insights into how the disease vectors defend themselves against infection. (Image: Rebecca Elias Abboud)

    In the work, which relies on disrupting the way that mosquitoes interact with or respond immunologically to the pathogens they pass on, Povelones, an assistant professor of pathobiology, has explored everything from dengue to Zika to heart worm to elephantiasis, and his discoveries have implications for targeting a much longer list of diseases. In a recent study, Povelones and colleagues developed a new model system for studying the transmission of diseases caused by kinetoplastids, a group of parasites that includes the causative agents of Chagas disease and leishmaniasis.

    “We think this could be a model for a number of important neglected diseases,” Povelones says.

    In the latest of his team’s work finding ways to activate mosquitoes’ immune system to prevent pathogen transmission, they’ve identified a strategy that both blocks heartworm and the parasite that causes elephantiasis.

    “These two diseases have very different behavior once they’re in the mosquito, so we’re still figuring out why this seems to work for both,” says Povelones. “But we’re very encouraged that it does.”

    Using these types of creative approaches is a common thread across the Vet School, and the researchers’ efforts and successes seem to be multiplying. To continue accelerating progress, the School is developing a plan to harness these strengths, working with existing entities such as the Center for Host-Microbial Interactions internally and cross-school units such as the Institute for Immunology.

    “We are a key part of the biomedical community at Penn and bring a valuable veterinary component to the table in confronting diseases of poverty,” says Scott.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Penn campus

    Academic life at Penn is unparalleled, with 100 countries and every U.S. state represented in one of the Ivy League’s most diverse student bodies. Consistently ranked among the top 10 universities in the country, Penn enrolls 10,000 undergraduate students and welcomes an additional 10,000 students to our world-renowned graduate and professional schools.

    Penn’s award-winning educators and scholars encourage students to pursue inquiry and discovery, follow their passions, and address the world’s most challenging problems through an interdisciplinary approach.

     
  • richardmitnick 11:40 am on December 5, 2019 Permalink | Reply
    Tags: "A newfound black hole in the Milky Way is weirdly heavy", , , , , Gran Telescopio Canarias, , LAMOST telescope in China, , That’s not just a record- it’s also a conundrum., With a mass of about 68 suns it is far heftier than other stellar-mass black holes (those with masses below about 100 suns) in and around the Milky Way scientists say.   

    From Science News: “A newfound black hole in the Milky Way is weirdly heavy” 

    From Science News

    November 27, 2019
    Christopher Crockett

    1

    A black hole (one illustrated) with a mass equal to about 68 suns has been found in the Milky Way, researchers say. That dark mass is much heavier than other similar black holes. NAOJ

    A heavyweight black hole in our galaxy has some explaining to do.

    With a mass of about 68 suns, it is far heftier than other stellar-mass black holes (those with masses below about 100 suns) in and around the Milky Way, scientists say. That’s not just a record, it’s also a conundrum. According to theory, black holes in our galaxy that form from the explosive deaths of massive stars — as this one likely did — shouldn’t be heavier than about 25 suns.

    The black hole is locked in orbit with a young blue star dubbed LB-1, which sits about 13,800 light-years away in the constellation Gemini, researchers found. Combing through data from the LAMOST telescope in China, Jifeng Liu, an astrophysicist at the Chinese Academy of Sciences in Beijing, and colleagues noticed that LB-1 repeatedly moves toward and away from Earth with great speed — a sign that the star orbits something massive.

    LAMOST telescope located in Xinglong Station, Hebei Province, China

    With additional observations from telescopes in Hawaii and the Canary Islands, the team mapped out the orbit and deduced that the star gets whipped around by a dark mass roughly 68 times as massive as the sun. Only a black hole fits that description, the team reports November 27 in Nature.

    Keck Observatory, operated by Caltech and the University of California, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level,

    Gran Telescopio Canarias at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, Spain, sited on a volcanic peak 2,267 metres (7,438 ft) above sea level

    “I never thought in my wildest dreams you could form a black hole this big [in the Milky Way],” says Michael Zevin, an astrophysicist at Northwestern University in Evanston, Ill. “If the observations pan out to be correct, this is really going to have people scratching their heads.”

    This black hole is not the heftiest in the Milky Way. That title goes to the behemoth in the center of the galaxy, a supermassive black hole in a class all its own with a mass of over 4 million suns. The mass of LB-1’s black hole is, however, on par with some of the black holes discovered recently by gravitational wave detectors, which sense ripples in spacetime from (among other things) merging pairs of black holes (SN: 2/17/16).

    But those black holes formed in far-off galaxies, probably in environments with a relative dearth of elements heavier than helium. The star LB-1 has a richer inventory of those elements, and presumably the star that formed its partner black hole had a similar stock. Stars with a greater abundance of heavy elements lose more of their mass to stellar winds, as those elements present a larger target to the radiation that drives those winds. Massive stars that form black holes also eject a lot of their mass during the supernova explosions that end their lives.

    “These two processes make very small black holes even out of very massive stars,” Liu says. But the black hole near LB-1 apparently didn’t get that memo.

    To make a black hole of 68 solar masses requires a reduction in the mass lost to stellar winds by a factor of five, Liu says. “We don’t know whether this is possible theoretically.”

    Alternatively, the black hole might have emerged from a failed supernova, an attempted stellar explosion that doesn’t have quite enough energy to hurl the star’s guts into space, leaving the gas to fall back into the black hole.

    The team also wonders if the black hole is the work of two stars. The scenario is speculative, Liu says, and “the odds are slim.” But in this story, LB-1 once orbited a snuggled-up pair of heftier stars that died and left behind two cores that merged into one black hole.

    It’s also possible that what appears to be a single 68-solar-mass black hole is actually two lighter black holes locked in a tight embrace. Such a pair would periodically nudge LB-1, giving it a subtle rocking motion that Liu and colleagues are searching for with other telescopes.

    Before getting caught up in potential origin stories, the observations need to be double-checked, Zevin cautions. “I wouldn’t put money down that it’s a definitive detection yet,” he says.

    The one catch, which the researchers do note, is that the calculated mass of the black hole depends on getting the distance to LB-1 correct. Their derived distance of 13,800 light-years — based on the star’s apparent brightness and calculations of its intrinsic luminosity — is about twice as far as the distance to the star determined by the Gaia satellite, a multiyear mission to create a precise 3-D map of over 1 billion stars in the Milky Way (SN: 5/9/18). If the Gaia distance is correct, then the black hole might be only 10 times as massive as the sun. (If the star is closer, then it’s less luminous, so less massive. That would mean that a lighter black hole is needed to explain the speed at which the star is getting whipped around.)

    That’s not necessarily a strike against the study. The researchers note that a much lower luminosity for the star would be at odds with its measured temperature. And if LB-1 is wobbling around a black hole, that would throw off the accuracy of the Gaia data, says Zevin. “But it is an important point that needs to be worked out.”

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 11:12 am on December 5, 2019 Permalink | Reply
    Tags: "There's an Easy Trick to Telling Stars and Planets Apart in the Sky", , , , ,   

    From Curiosity: “There’s an Easy Trick to Telling Stars and Planets Apart in the Sky” 

    Curiosity Makes You Smarter

    From From Curiosity

    January 25, 2018 [Just now in social media]
    Cody Gough

    Look up in the night sky, and you’ll see millions of stars and a handful of planets. How can you tell the difference? Just remember: The classic lullaby doesn’t go “twinkle, twinkle, little planet.” There’s a reason for that.
    Planet Light, Planet Bright, First Planet I See Tonight

    Stars twinkle because of the massive distance between them and Earth. And we mean massive: Our sun’s closest stellar neighbors are more than four light-years away. Because of that great distance, we essentially see each star as a single point of light — a shape with almost zero diameter. Once it hits Earth, that starlight is refracted by the various differences of temperature and density as it makes its way through our atmosphere. The refraction is greater than the star’s tiny diameter, so it’s easy to see — and to us, it looks like twinkling. The scientific term for this is astronomical scintillation.

    Our sun and the planets in our solar system are much closer than the rest of the stars in the sky. Earth’s atmosphere refracts light from those, too, but since they’re a lot closer to us, they show up with a larger diameter than those faraway stars. This makes them look more like tiny disks than pinpoints — something you might not notice with the naked eye but that’s easy to see with binoculars or a telescope. The light from one edge of that disk might be forced to “zig” in one direction, but light from the opposite side might “zag” in an opposite direction. Those opposing directions effectively cancel each other out, producing a steady shine that doesn’t twinkle like a little star.

    1

    Lost in Space

    Experienced stargazers can figure out which objects are stars and which are planets just by observing which ones twinkle and which ones don’t. But keep in mind that sometimes planets twinkle, too, if you spot them low in the sky. That’s because when you look toward the horizon, you’re looking through more atmosphere than when you’re looking straight up. This means more light refraction, which means more of that astronomical scintillation — aka twinkling.

    If you ever get a chance to visit outer space, of course, then you can expect to see a distinct lack of twinkling to go along with that distinct lack of atmosphere. The lack of light refraction from the atmosphere is why we put telescopes up in space, helping behemoths like the Hubble Space Telescope produce the brilliant and crisp images of the universe that make it famous. But that’s not the only difference you’ll notice in space.

    NASA astronaut James Reilly told SpaceFlight Insider that once your eyes adjust during a spacewalk, “you can start to notice that some of the stars have colors we don’t see here on the ground.

    So you see these pastel colors — light yellows, light pinks, light oranges, even light red ones and light blues — there’s all kinds of colors that you can see in these stars that you can’t see here because it’s filtered out by the atmosphere.”

    Twinkling Is in the Eye of the Beholder

    One other quirk of stargazing is that bright objects in the sky look different to everyone — even different telescopes. The four points emanating from stars in images from the Hubble Telescope, for example, happen in any telescope that focuses light with a mirror rather than with a lens. The four points are known as diffraction spikes and are caused by the light’s path being diffracted slightly as it passes by the cross-shaped struts that support the telescope’s secondary mirror.

    Distortion isn’t just for telescopes. Remember, the human eye has a lens, too! Those lenses have subtle structural imperfections called suture lines that show up where the lens fibers meet together. These imperfections leave a particular imprint on light as it reaches your eyes, so even though stars actually appear as tiny round dots, our lenses have smeared the light into a star-like shape by the time the light reaches our retinas. Because we’re all different, every eye on Earth will see a slightly different star-like smear depending on the exact nature of its suture lines; even your own left and right eyes will differ. But every eye sees the same shape for every single star. Try closing one eye the next time you’re looking up at the sky and see what happens!

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Curiosity Makes You Smarter

    Curiosity is on a mission to make learning easier and more fun than it has ever been. Our goal is to ignite curiosity and inspire people to learn. Each day, we create and curate engaging topics for millions of lifelong learners worldwide.

    Experience Curiosity on our website, through our apps and across social media. We designed Curiosity with your busy life in mind. Our editors find interesting and important topics that you’ll want to know more about, and introduce you to the best ways to keep learning.

    We hope you make Curiosity part of your daily digital diet. Never stop learning!

     
  • richardmitnick 10:45 am on December 5, 2019 Permalink | Reply
    Tags: "Seal Takes Ocean Heat Transport Data to New Depths", ,   

    From NASA JPL-Caltech: “Seal Takes Ocean Heat Transport Data to New Depths” 

    NASA JPL Banner

    From NASA JPL-Caltech

    December 4, 2019
    Arielle Samuelson
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-0307
    arielle.a.samuelson@jpl.nasa.gov

    Written by Esprit Smith, NASA’s Earth Science News team

    1
    A tagged elephant seal basks on Kerguelen Island, a French territory in the Antarctic. Elephant seals are tagged as part of a French research program called SO-MEMO (Observing System – Mammals as Samplers of the Ocean Environment), operated by the French National Center for Scientific Research (CNRS). The tags – actually, sensors with antennas – are glued to the seals’ heads in accordance with established ethical standards when the animals come ashore either to breed or to molt. The researchers remove the tags to retrieve their data when the seals return to land. If they miss a tag, it drops off with the dead skin in the next molting season. Credit: Sorbonne University/Etienne Pauthenet

    The Antarctic Circumpolar Current flows in a loop around Antarctica, connecting the Atlantic, Pacific and Indian oceans. It is one of the most significant ocean currents in our climate system because it facilitates the exchange of heat and other properties among the oceans it links.

    But how the current transfers heat, particularly vertically from the top layer of the ocean to the bottom layers and vice versa, is still not fully understood. This current is very turbulent, producing eddies – swirling vortices of water similar to storms in the atmosphere – between 30 to 125 miles (50 to 200 kilometers) in diameter. It also spans some 13,000 miles (21,000 kilometers) through an especially remote and inhospitable part of the world, making it one of the most difficult currents for scientists – as least those of the human variety – to observe and measure.

    Luckily for Lia Siegelman, a visiting scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, the rough seas posed no challenge for her scientific sidekick: a tagged southern elephant seal.

    Equipped with a specialized sensor reminiscent of a small hat, the seal swam more than 3,000 miles (4,800 kilometers) on a three-month voyage, much of it through the turbulent, eddy-rich waters of the Antarctic Circumpolar Current. The seal made around 80 dives at depths ranging from 550 to 1,090 yards (500 to 1,000 meters) per day during this time. All the while, it collected a continuous stream of data that has provided new insight into how heat moves vertically between ocean layers in this volatile region – insight that brings us one step closer to understanding how much heat from the Sun the ocean there is able to absorb.

    For a new paper published recently in Nature Geoscience, Siegelman and her co-authors combined the seal’s data with satellite altimetry data. The satellite data of the ocean surface showed where the swirling eddies were within the current and which eddies the seal was swimming through. Analyzing the combined dataset, the scientists paid particular attention to the role smaller ocean features played in vertical heat transport. Siegelman was surprised by the results.

    “These medium-sized eddies are known to drive the production of small-scale fronts – sudden changes in water density similar to cold and warm fronts in the atmosphere,” she said. “We found that these fronts were evident some 500 meters [550 yards] into the ocean interior, not just in the surface layer like many studies suggest, and that they played an active role in vertical heat transport.”

    According to Siegelman, their analysis showed that these fronts act like ducts that carry a lot of heat from the ocean interior back to the surface. “Most current modeling studies indicate that the heat would move from the surface to the ocean interior in these cases, but with the new observational data provided by the seal, we found that that’s not the case,” she said.

    2
    This 3D schematic shows how a tagged elephant seal collects data by swimming long distances and diving to great depths through turbulent waters near Antarctica. Satellite data are used to identify characteristics of the waters through which the seals swim. The blue represents cold, dense water; the red areas are less dense and typically warmer. Credit: Tandi Reason Dahl
    Why It Matters

    The ocean surface layer can absorb only a finite amount of heat before natural processes, like evaporation and precipitation, kick in to cool it down. When deep ocean fronts send heat to the surface, that heat warms the surface layer and pushes it closer to its heat threshold. So essentially, in the areas where this dynamic is present, the ocean isn’t able to absorb as much heat from the Sun as it otherwise could.

    Current climate models and those used to estimate Earth’s heat budget don’t factor in the effects of these small-scale ocean fronts, but the paper’s authors argue that they should.

    “Inaccurate representation of these small-scale fronts could considerably underestimate the amount of heat transferred from the ocean interior back to the surface and, as a consequence, potentially overestimate the amount of heat the ocean can absorb,” Siegelman said. “This could be an important implication for our climate and the ocean’s role in offsetting the effects of global warming by absorbing most of the heat.”

    The scientists say this phenomenon is also likely present in other turbulent areas of the ocean where eddies are common, including the Gulf Stream in the Atlantic Ocean and the Kuroshio Extension in the North Pacific Ocean.

    Although their results are significant, Siegelman says more research is needed to fully understand and quantify the long-term effects these fronts may have on the global ocean and our climate system. For example, the study is based on observations in the late spring and early summer. Results may be more pronounced during winter months, when these small-scale fronts tend to be stronger. This body of research will also benefit from additional studies in other locations.

    For more information on how the elephant seal data were acquired, see:

    https://climate.nasa.gov/news/2871/data-with-flippers-studying-the-ocean-from-a-seals-point-of-view/

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA JPL Campus

    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, 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

     
  • richardmitnick 10:30 am on December 5, 2019 Permalink | Reply
    Tags: "Caltech Undergrads Build Robot for DARPA Challenge", Balto competed in the August 2019 tunnel-navigation section of the DARPA SubT Challenge., Balto is about half the size of the more powerful Huskies and costs an order of magnitude less., Balto-the robot truck, , , Like other teams CoSTAR has a diverse fleet of different types of robots including a hybrid rolling/flying robot; a tracked tank-like robot; and small flying drones that can navigate tunnels., Team CoSTAR, Truck-like robot will be a probe for exploring underground arenas.   

    From Caltech: “Caltech Undergrads Build Robot for DARPA Challenge” 

    Caltech Logo

    From Caltech

    December 02, 2019
    Robert Perkins
    (626) 395‑1862
    rperkins@caltech.edu

    Truck-like robot will be a probe for exploring underground arenas.

    1
    Caltech seniors Jake Ketchum and Alexandra (Sasha) Bodrova work on the superstructure that holds Balto’s critical custom components.

    A robot designed and built by undergraduate students at Caltech working with graduate students at Caltech and JPL, which Caltech manages for NASA, took to the field in the first phase of the Defense Advanced Research Projects Agency (DARPA) Subterranean (SubT) Challenge this summer, where the Caltech-JPL team took second place.

    The SubT Challenge is an international competition sponsored by DARPA to advance technologies to autonomously map, navigate, and search underground environments. Teams earn points by accurately identifying and mapping artifacts that represent items a first responder might find underground: items like a cell phone, backpack, or even a thermal manikin that simulates a survivor.

    The August competition, a tunnel-navigation task, was the first of three stages leading up to a final event in August 2021. In the second stage, to be held in Februrary 2020, the team will compete in an urban underground environment; in the third, in August 2020, they move to a cave. Teams that fail to perform well enough in any stage can be disqualified. For the final, the remaining teams will compete in an event that combines all three environments.

    3
    Balto competed in the August 2019 tunnel-navigation section of the DARPA SubT Challenge.

    In the tunnel competition, there were 11 teams, most made up of consortia of research institutions and private companies. Team CoSTAR (Collaborative SubTerranean Autonomous Resilient Robots), led by JPL Robotics Technologist Ali Agha, includes JPL, Caltech, MIT, the Korea Advanced Institute of Science and Technology (KAIST), and Sweden’s Lulea University of Technology.

    Like other teams, CoSTAR has a diverse fleet of different types of robots, including a hybrid rolling/flying robot, a tracked tank-like robot, and small flying drones that can navigate tunnels. The vehicles work together to perform assigned tasks: for example, a ground robot might begin exploration but come to an unnavigable roadblock, at which point a flying drone might be called in to explore beyond the roadblock. The backbone of the CoSTAR fleet is a group of simple, efficient, and reliable truck-like four-wheeled robots called the Huskies.

    The newest addition to the fleet, added this summer, looks like the runt of the Husky litter. Dubbed Balto after a famous rescue sled dog, the new robot was built atop a commercial radio control car. Caltech’s Joel Burdick, the Richard L. and Dorothy M. Hayman Professor of Mechanical Engineering and Bioengineering and JPL research scientist, and the leader of the Caltech section of the CoSTAR team, decided that using an off-the-shelf R/C as a base would fast track the development of Balto since the team was able to start with a vehicle that already had a sturdy suspension and powerful electric motor.

    Balto is about half the size of the more powerful Huskies, and costs an order of magnitude less. The final product is a vehicle that is about a meter long, weighs about 12 kilograms, and is capable of navigating slopes of up to 40 degrees. Because it is so light, it is also a good deal faster than the Huskies, and can reach speeds of 55 miles per hour.

    “The idea was to create a ground-based scout,” Burdick says. “The drones are our air-based scouts, and Balto is our eyes and ears on the ground. It’s light, cheap, and fast. It can get in, find out what’s going on, and help us to make decisions about how to proceed.” Balto can also fill in as a substitute in emergencies. For example, since wireless signals are often blocked in underground environments, SubT competitors have had to build ad hoc wireless networks by using robots stationed along the tunnel as wireless nodes so that the robots can communicate with one another. If one of the nodes fails, Balto is capable or quickly rushing in to fill in the gap.

    Initial work on Balto began in CS/EE/ME 75, Multidisciplinary Systems Engineering, a cross-discipline special projects undergraduate class at Caltech. This spring, a team of about a half-dozen undergraduate students began work on the off-the-shelf car that would become Balto. First, they stripped the body off of the vehicle’s chassis and began designing a removable superstructure that would house all of the equipment necessary to transform an R/C car into a self-guided robot explorer. The superstructure of Balto, which was built using milling machines and 3-D printers at Caltech, can be lifted as a single unit off of the chassis. Balto features a towering LIDAR unit (a detection and ranging technology in which the vehicle’s surroundings scanned with laser beams) that works in tandem with twin cameras to “see” its surroundings, a radio receiver that allows it to communicate with the rest of the fleet, and an on-board computer that contains the programming that makes the vehicle autonomous.

    “The chassis is largely stock, but Balto’s electrical and control systems have been entirely replaced,” says Jake Ketchum, now a Caltech senior, who led the CS/EE/ME 75 class team and continued to work on Balto through the Summer Undergraduate Research Fellowship (SURF) program.

    The team also swapped out the vehicle’s simple motor controller to an upgraded version that gives the autonomous guidance system more precise control over the vehicle’s speed, which allows them to more accurately place Balto where it is needed.

    “Balto was tested in the field and, in the fully autonomous mode, successfully navigated tunnels that were more than 100 meters long,” says Alexandra (Sasha) Bodrova, now a Caltech senior who also worked on Balto through the SURF program. “Balto detected and avoided obstacles such as rocks and rails, made sharp turns, and then returned to the starting line, in reverse.”

    4
    Alexandra Bodrova fabricates custom parts for Balto.

    At the beginning of the summer, the Balto team was expanded to include graduate student researchers Nikhilesh Alatur and Anushri Dixit, who were tasked with incorporating autonomous control to the vehicle and integrating it into CoSTAR’s fleet.

    Alatur and Dixit were among the CoSTAR team members who traveled to Pittsburgh for the first leg of the SubT Challenge, held at the National Institute for Occupational Safety and Health (NIOSH) Mining Program’s Safety Research Coal Mine and Experimental Mine, a federal site where mine-related safety and health research is conducted.

    The competition took place over the course of four days, with each team given one hour per day to complete specific tasks, most of which involved finding and engaging with objects of interest, like a backpack or a lever arm. While a small group of 10 engineers launched the robots at the mouth of the mine, most of the rest of the team, including Alatur and Dixit, watched the action via a livestream from the conference room near the mine.

    “Everyone worked in shifts, fixing robots during the night and watching the competition or sleeping during the day,” Dixit says.

    “Every day, up to 20 minutes before the start of our run, we weren’t even sure the team was going to get off of the line,” Burdick says, describing how the team would scramble to address software and hardware issues on its completely custom robots.

    Given the importance of the Huskies to the fleet, the first order of business was always to make sure they made it into the field. For the first three days of the competition, Balto mainly warmed the bench as the team deployed its other vehicles.

    Then, on the fourth and final day of competition, the decision was made to send in Balto.

    “It was pretty intense. There were five or six people gathered around the screen, and as soon as Balto went in, everyone started screaming and shouting and cheering,” says Alatur, graduate student at ETH Zurich who is spending a six-month stint on the CoSTAR team as a student researcher at JPL. “We were happy to see that Balto was sent in for the last few minutes of the competition and could make its debut in a DARPA challenge.” During the competition, Alatur and Dixit stayed in constant text contact with Ketchum and Bodrova, who watched the livesteam from Caltech and were equally excited to see the robot take to the field.

    Balto’s mission was limited; as Burdick puts it, the main goal was to see how the robot performed and to gather data that can be used to improve it for the next round of the competition. The original plan was that Balto would be tasked with positioning communication nodes—basically, wifi signal boosters that enable all of the robots in the tunnel to stay connected—but it turned out to be unnecessary. Instead, Balto drove 125 meters into the tunnel and stopped, just as directed, and acted as a wifi unit to relay signals as necessary. “In the end, we didn’t truly need it, but it did its job well,” Burdick says. “And more importantly, we gained data about Balto’s performance that will help us down the line.”

    Because of Balto’s speed, diminutive size, and ruggedness, Burdick predicts a growing role for the little robot in future competitions. This year’s CS/EE/ME 75 class will continue to refine Balto, as well as other new vehicles to be used in the next phases of the competition in February and August, 2020.

    “I think we’re going to be grateful to have a small, tough robots like Balto when we get to the final event in 2021,” he says.

    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 California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

    Caltech campus

     
  • richardmitnick 9:51 am on December 5, 2019 Permalink | Reply
    Tags: "Looking for exoplanet life in all the right spectra", , , , ,   

    From Cornell Chronicle: “Looking for exoplanet life in all the right spectra” 

    From Cornell Chronicle

    December 4, 2019
    Blaine Friedlander
    bpf2@cornell.edu

    1
    While astronomers don’t know what the Earth-like exoplanet Proxima b looks like, this artistic impression presents a view of the possible surface. New, upcoming large telescopes on Earth will soon explore atmospheres on exoplanets – like Proxima b – for signatures of life. ESO/M. Kornmesser

    A Cornell senior has come up with a way to discern life on exoplanets loitering in other cosmic neighborhoods: a spectral field guide.

    Zifan Lin ’20 has developed high-resolution spectral models and scenarios for two exoplanets that may harbor life: Proxima b, in the habitable zone of our nearest neighbor Proxima Centauri; and Trappist-1e, one of three possible Earth-like exoplanet candidates in the Trappist-1 system.

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

    The paper, co-authored with Lisa Kaltenegger, associate professor of astronomy and director of Cornell’s Carl Sagan Institute, published Nov 18 in Monthly Notices of the Royal Astronomical Society.

    “In order to investigate whether there are signs of life on other worlds, it is very important to understand signs of life that show in a planet’s light fingerprint,” Lin said. “Life on exoplanets can produce a characteristic combination of molecules in its atmosphere – and those become telltale signs in the spectra of such planets.

    “In the near future we will be seeing the atmosphere of these worlds with new, sophisticated ground-based telescopes, which will allow us to explore the exoplanet’s climate and might spot its biota,” he said.

    In the search for habitable worlds, “M dwarf” stars catch astronomers’ eyes, since the local universe teems with these suns, which make up 75% of the nearby cosmos, according to Lin.

    Throughout the Milky Way, our home galaxy, astronomers have discovered more than 4,000 exoplanets, some in their own suns’ habitable zone – an area that provides conditions suitable for life.

    To explore the atmosphere of these places, scientists need large next-generation telescopes, such as the Extremely Large Telescope (ELT), currently under construction in northern Chile’s Atacama Desert;

    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).

    it is expected to be operational in 2025. Scientists can aim the mammoth eyepiece – with a flawless primary mirror about half the size of a football field – at Proxima b and Trappist-1e. The future telescope will have more than 250 times the light-gathering power of the Hubble Space Telescope.

    Lin and Kaltenegger said the high-resolution spectrographs from the ELT can discern water, methane and oxygen for both Proxima b and Trappist-1e, if these planets are like our own pale blue dot.

    About 4 light-years from Earth, Proxima b can be resolved by new ground-based telescopes, giving astronomers an edge in observing this close-by world.

    “Assuming these worlds could be like a young or modern Earth, with similar or eroded atmospheres,” Kaltenegger said. “Zifan has generated a database of light fingerprints for these worlds, a guide to allow observers to learn how to find signs of life, if they are there.

    Said Kaltenegger: “We are providing a template on how to find life on these worlds, if it exists.”

    Funding for this research was provided by the Carl Sagan Institute and the Breakthrough Foundation.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
  • richardmitnick 9:36 am on December 5, 2019 Permalink | Reply
    Tags: "Composition of gas giant planets not determined by host star study finds", , , , , ,   

    From UC Santa Cruz and Carnegie Institution for Science: “Composition of gas giant planets not determined by host star, study finds” 

    UC Santa Cruz

    From UC Santa Cruz

    and

    Carnegie Institution for Science
    Carnegie Institution for Science

    December 03, 2019
    Natasha Metzler, Carnegie
    stephens@ucsc.edu

    Research led by astronomers at UC Santa Cruz and Carnegie Institution for Science has implications for understanding how planets form.

    1
    An artist’s conception of a young star surrounded by a primordial rotating disk of gas and dust from which planets can form. (Illustration by Robin Dienel, courtesy of the Carnegie Institution for Science)

    A surprising analysis of the compositions of gas giant exoplanets and their host stars shows that there isn’t a strong correlation between their compositions when it comes to elements heavier than hydrogen and helium. The new findings, published in The Astronomical Journal, have important implications for understanding the planetary formation process.

    In their youths, stars are surrounded by a rotating disk of gas and dust from which planets are born. Astronomers have long wondered how much a star’s makeup determines the raw material from which planets are constructed—a question that is easier to probe now that we know the galaxy is teeming with exoplanets.

    “Understanding the relationship between the chemical composition of a star and its planets could help shed light on the planetary formation process,” explained first author Johanna Teske of the Carnegie Institution for Science.

    For example, previous research indicated that the occurrence of gas giant planets increases around stars with a higher concentration of heavy elements, those elements other than hydrogen and helium. This is thought to provide evidence for one of the primary competing theories for how planets form, which proposes that gas giant planets are built from the slow accretion of disk material until a core about 10 times Earth’s mass is formed. At this point, the solid baby planetary interior is able to surround itself with helium and hydrogen gas, birthing a mature giant planet.

    “Previous work looked at the relationship between the presence of planets and how much iron exists in the host star, but we wanted to expand that to include the heavy element content of the planets themselves, and to look at more than just iron,” explained co-author Daniel Thorngren, who completed much of the work as a graduate student at UC Santa Cruz and is now a Trottier Postdoctoral Fellow at the Université de Montréal.

    Teske, Thorngren and their colleagues—Jonathan Fortney of UC Santa Cruz, Natalie Hinkel of the Southwest Research Institute, and John Brewer of San Francisco State University—compared the bulk heavy element content of 24 cool, gas giant planets to the abundances of “planet forming elements” carbon, oxygen, magnesium, silicon, iron, and nickel in their 19 host stars (some stars host multiple planets).

    They were surprised to find that there was no correlation between the amount of heavy elements in these giant planets and the amount of these planet forming elements in their host stars. So how can astronomers explain the established trend that stars rich in heavy elements are more likely to host gas giant planets?

    “Unraveling this discrepancy could reveal new details about the planet formation process,” explained coauthor Fortney. “For example, what other factors are contributing to a baby planet’s composition as it forms? Perhaps its location in the disk and how far it is from any neighbors. More work is necessary to answer these crucial questions.”

    One clue may come from the authors’ combined results bundling the heavy elements into groupings that reflect their characteristics. The authors saw a tentative correlation between a planet’s heavy elements and its host star’s relative abundance of carbon and oxygen, which are called volatile elements, versus the rest of the elements included in this study, which fall into the group called refractory elements. These terms refer to the elements’ low boiling points (volatility) or their high melting points (in the case of the refractory elements). Volatile elements may represent an ice-rich planetary composition, whereas refractory elements may indicate a rocky composition.

    “I’m excited to explore this tentative result further, and hopefully add more information to our understanding of the relationships between star and planetary compositions from upcoming missions like NASA’s James Webb Space Telescope, which will be able to measure elements in exoplanet atmospheres,” Teske said.

    This work was supported by a NASA Hubble Fellowship and a NASA XRP grant.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

    UCSC Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft)

    .

    UC Observatories Lick Autmated Planet Finder, fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA

    The UCO Lick C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft)

    UC Santa Cruz campus

    UCSC is the home base for the Lick Observatory.

    Lick Observatory's Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building
    Lick Observatory’s Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building

     
  • richardmitnick 4:58 pm on December 4, 2019 Permalink | Reply
    Tags: "Locally sourced neutrinos? IceCube takes a look", , , , The “local universe” is defined as the volume of space surrounding the Milky Way in which most galaxies are visible to our telescopes—extending up to 300 million light-years away from us., The IceCube Neutrino Observatory detected an astrophysical neutrino—a high-energy particle from outer space—from a flaring blazar approximately 5 billion light-years away.,   

    From U Wisconsin IceCube Collaboration: “Locally sourced neutrinos? IceCube takes a look” 

    U Wisconsin ICECUBE neutrino detector at the South Pole

    From From U Wisconsin IceCube Collaboration

    03 Dec 2019
    Madeleine O’Keefe


    IceCube explained

    Neutrinos from blazar

    What does “local” mean to you? Maybe your local coffee shop is around the corner from your office. Maybe your local pharmacy is a 15-minute walk from your home. But on the scale of the cosmos, the definition of local is stretched, to say the least. In fact, the “local universe” is defined as the volume of space surrounding the Milky Way in which most galaxies are visible to our telescopes—extending up to 300 million light-years away from us.

    When it comes to analyses done by the IceCube Collaboration, this is local indeed. After all, the IceCube Neutrino Observatory detected an astrophysical neutrino—a high-energy particle from outer space—from a flaring blazar approximately 5 billion light-years away. That source, called TXS 0506+056, is still the only confirmed source of astrophysical neutrinos, but it certainly does not explain all of the astrophysical neutrinos we see.

    IceCube has not yet found neutrino sources within our galaxy, but there may be sources that are not too much farther out. To test this possibility, the IceCube Collaboration recently performed an analysis scouring the local universe for potential neutrino sources. They conducted two different searches that looked for correlations between neutrino emission and dense regions in a catalog of galaxies called the 2MASS Redshift Survey (2MRS). While they did not find significant sources, they were able to put constraints on neutrino emission from nearby galaxies, which they present in a paper recently submitted to the Journal of Cosmology and Astroparticle Physics.

    2
    New limits as a result of this search, shown in two ways. Left: the limit on total flux as a function of the energy spectrum (results of the template analysis). Right: the limit on density of sources as a function of source luminosity (results of the multiplets analysis). Credit: IceCube Collaboration

    Neutrinos are tricky. They are fundamental particles but have no charge and interact very weakly, which means they can fly through light-years of matter without giving any hint that they have passed. The IceCube Neutrino Observatory was built to try and “catch” them. Embedded in the South Pole ice are over 5,000 optical modules that will light up when triggered by a flash of radiation caused by a neutrino decaying into another particle. If the neutrino decays into a particle called a muon, that muon may trigger multiple optical modules, leaving a trail of signals that scientists can trace toward the neutrino’s source—whatever that is.

    While IceCube analyses typically focus on looking to see if neutrinos originate from a few bright, intense, and faraway objects (like blazars), some researchers decided to look at the local universe, including Steve Sclafani of Drexel University in Philadelphia, PA. “We have one advantage when focused on the local universe: At the closest distances, large-scale structures—like superclusters, the supergalactic plane, filamentary structure, and local voids—exist,” he says.

    This paper describes two analyses that searched for excess neutrinos correlated with local large-scale structures. Each search tested a different hypothesis about how the neutrinos were emitted. The “template analysis” created an all-sky template of the local galaxy density to test whether the matter of the local universe was acting as a target, where ultra-high-energy cosmic rays would interact and produce neutrinos. The “multiplet analysis” tested the hypothesis that clusters of neutrinos called “multiplets” are generated by neutrino sources within the local universe.

    “The motivation for this analysis is rather simple: After 10 years of detecting astrophysical neutrinos, we would like to figure out their origin,” says Étienne Bourbeau of the Niels Bohr Institute in Copenhagen, Denmark, who led the multiplet search.

    The simplest explanation, he says, is that neutrinos are produced by astronomical objects made up of normal matter. “If that’s true, then you would expect neutrinos to come from the places in the sky where there is the most stuff,” he says.

    To find where the most “stuff” is in the universe, researchers can use catalogs of galaxies established by other astronomical observatories—here, the 2MRS survey. Their goal was to see whether neutrinos detected by IceCube correlated with our best estimate of matter density in the local universe. Galaxies are not uniformly distributed in our local universe, so if neutrinos really do come from the galaxies mapped by 2MRS, there should be more neutrino clusters from specific regions in the sky.

    First, they defined the IceCube neutrino emission using an existing IceCube analysis, the seven-year point source search.

    3
    Template analysis’s map of local galaxy density from 2MRS. Credit: IceCube Collaboration

    For the template analysis, Sclafani and his collaborators took the 2MRS infrared catalog, weighted each galaxy, and created a template of the sky. Next, they looked for any correlation between our neutrino sky and the 2MRS sky—in other words, a correlation between neutrino emission and the large-scale features.

    Meanwhile, for the multiplet analysis, Bourbeau and his collaborators used 2MRS in a slightly different way. They tested whether the incidence of neutrino clusters in IceCube correlates significantly with the density of galaxies observed in the 2MRS catalog. They used a previously published analysis of neutrino clustering from the seven-year sample, then compared the distribution of these clusters to 10,000 random distributions of the same number of multiplets.

    4
    Normalized distribution of a selection of galaxies, taken from the 2MRS catalog (top), and location of selected multiplets, where each yellow dot represents the location of a local maximum from the seven-year point source map (bottom). Credit: IceCube Collaboration

    Ultimately, neither analysis found any significant correlation between astrophysical neutrinos or multiplets and the galaxies of the 2MRS catalog. Based on that, however, the researchers were able to put boundaries on the density and average luminosity of any hypothetical population of neutrino sources located within our local universe.

    “Although this work didn’t turn anything up, it established methods for this kind of search, and as new all-sky surveys arrive we can revisit this analysis and see if we are able to detect local galaxy neutrinos,” says Sclafani. “Even though we have one source, there is still a push to explain where all our astrophysical neutrinos are coming from.”

    Of course, Bourbeau points out, it could be possible that neutrino sources are much farther out in space. After all, TXS 0506+056 is 5 billion light-years away. Wherever the sources are, IceCube will keep looking.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition
    IceCube is a particle detector at the South Pole that records the interactions of a nearly massless sub-atomic particle called the neutrino. IceCube searches for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma ray bursts, and cataclysmic phenomena involving black holes and neutron stars. The IceCube telescope is a powerful tool to search for dark matter, and could reveal the new physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams. IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.

    IceCube employs more than 5000 detectors lowered on 86 strings into almost 100 holes in the Antarctic ice NSF B. Gudbjartsson, IceCube Collaboration

    Lunar Icecube

    IceCube DeepCore annotated

    IceCube PINGU annotated


    DM-Ice II at IceCube annotated

     
  • richardmitnick 4:25 pm on December 4, 2019 Permalink | Reply
    Tags: "Discovering the Top Quark", , , FNAL Tevatron CDF, , , , ,   

    From particlebites: “Discovering the Top Quark” 

    particlebites bloc

    From particlebites

    December 3, 2019
    Adam Green

    This post is about the discovery of the most massive quark in the Standard Model, the Top quark. Below is a “discovery plot” [1] from the Collider Detector at Fermilab collaboration (CDF). Here is the original paper [Physical Review Letters].

    FNAL/Tevatron CDF detector

    FNAL/Tevatron tunnel

    FNAL/Tevatron map

    1
    This plot confirms the existence of the Top quark. Let’s understand how.

    For each proton collision that passes certain selection conditions, the horizontal axis shows the best estimate of the Top quark mass. These selection conditions encode the particle “fingerprint” of the Top quark. Out of all possible proton collisions events, we only want to look at ones that perhaps came from Top quark decays. This subgroup of events can inform us of a best guess at the mass of the Top quark. This is what is being plotted on the x axis.

    On the vertical axis are the number of these events.

    The dashed distribution is the number of these events originating from the Top quark if the Top quark exists and decays this way. This could very well not be the case.

    The dotted distribution is the background for these events, events that did not come from Top quark decays.

    The solid distribution is the measured data.

    To claim a discovery, the background (dotted) plus the signal (dashed) should equal the measured data (solid). We can run simulations for different top quark masses to give us distributions of the signal until we find one that matches the data. The inset at the top right is showing that a Top quark of mass of 175GeV best reproduces the measured data.

    Taking a step back from the technicalities, the Top quark is special because it is the heaviest of all the fundamental particles. In the Standard Model, particles acquire their mass by interacting with the Higgs. Particles with more mass interact more with the Higgs. The Top mass being so heavy is an indicator that any new physics involving the Higgs may be linked to the Top quark.

    References / Further Reading

    [1] – Observation of Top Quark Production in pp Collisions with the Collider Detector at Fermilab – This is the “discovery paper” announcing experimental evidence of the Top.

    [2] – Observation of tt(bar)H Production [Physical Review Letters]– Who is to say that the Top and the Higgs even have significant interactions to lowest order? The CMS collaboration finds evidence that they do in fact interact at “tree-level.”

    [2] – The Perfect Couple: Higgs and top quark spotted together – This article further describes the interconnection between the Higgs and the Top.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    What is ParticleBites?

    ParticleBites is an online particle physics journal club written by graduate students and postdocs. Each post presents an interesting paper in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.

    The papers are accessible on the arXiv preprint server. Most of our posts are based on papers from hep-ph (high energy phenomenology) and hep-ex (high energy experiment).

    Why read ParticleBites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. With each brief ParticleBite, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in particle physics.

    Who writes ParticleBites?

    ParticleBites is written and edited by graduate students and postdocs working in high energy physics. Feel free to contact us if you’re interested in applying to write for ParticleBites.

    ParticleBites was founded in 2013 by Flip Tanedo following the Communicating Science (ComSciCon) 2013 workshop.

    2
    Flip Tanedo UCI Chancellor’s ADVANCE postdoctoral scholar in theoretical physics. As of July 2016, I will be an assistant professor of physics at the University of California, Riverside

    It is now organized and directed by Flip and Julia Gonski, with ongoing guidance from Nathan Sanders.

     
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