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The Truth is Out There: New Online SETI Tool Tracks Alien Searches
Donnerstag, 17.01.2019, 01:29:56 Uhr
Moscow (Sputnik) Jan 16, 2019 -
A new online tool will assist amateurs and professionals in digging through massive data banks to uncover new clues into the search for alien life.As researchers around the globe continue their quest to find physical proof of extraterrestrial life, the Search for Extraterrestrial Intelligence Institute (SETI) has introduced new software to assist anyone with an interest in 'what's out there' to study the data and draw their own conclusions.SETI co-founder Jill Tarter - the inspiration for Ellie Arroway, the fictional character in Carl Sagan's blockbuster 1985 science-fiction novel 'Contact' (which became a popular Jodie Foster movie in 1997) - has announced a new web tool called Technosearch, enabling anyone to log on and view, study or mine every publication in the entire database, according to Space.com.The database includes the document covering every SETI search, beginning in 1960 and continuing to the present day. In keeping with the mission statement of the organization - in part - 'to apply the knowledge gained', users can gain access to all the information to date and draw their own conclusions.SETI's January 9 database access announcement at the 223rd meeting of the American Astronomical Society seeks to have users from all walks of life work together to keep the Technosearch tool and the enormous reams of data up to date and 100 percent accurate, according to the website.By aggregating all searches conducted in the sky to date, SETI hopes the new tool will reveal currently-unresolved patterns or hints that could point to new evidence indicating sentient life beyond our planet."I started keeping this search archive when I was a graduate student," noted Tarter, cited by Space.com."Some of the original papers were presented at conferences or appear in obscure journals that are difficult for newcomers to the SETI field to access, Tartar said, adding, "I'm delighted that we now have a tool that can be used by the entire community and a methodology for keeping it current."Developed in collaboration with interns working under the Research Experience for Undergraduates (REU), themselves laboring under the oversight of Penn State University exoplanet and star researcher Jason Wright, Technosearch will play a prominent role in the ongoing use of SETI data, according to former REU student Andrew Garcia, cited by Space.com."I've become convinced that Technosearch will become an important instrument for astronomers and amateurs interested in exploring the cosmos for indications of other technological civilizations," Garcia stated."We can't know where to look for evidence tomorrow if we don't know where we have already looked," he observed.Source: Sputnik News
Double star system flips planet-forming disk into pole position
Donnerstag, 17.01.2019, 01:29:56 Uhr
Warwick UK (SPX) Jan 17, 2019 -
New research led by an astronomer at the University of Warwick has found the first confirmed example of a double star system that has flipped its surrounding disc to a position that leaps over the orbital plane of those stars. The international team of astronomers used the Atacama Large Millimeter/sub-millimeter Array (ALMA) to obtain high-resolution images of the Asteroid belt-sized disc.The overall system presents the unusual sight of a thick hoop of gas and dust circling at right angles to the binary star orbit. Until now this setup only existed in theorists' minds, but the ALMA observation proves that polar discs of this type exist, and may even be relatively common.The new research is published Jan 14 by Royal Society University Research Fellow Dr Grant M. Kennedy of the University of Warwick's Department of Physics and Centre for Exoplanets and Habitability in Nature Astronomy in a paper entitled "A circumbinary protoplanetary disc in a polar configuration".Dr Grant M. Kennedy of the University of Warwick said: "Discs rich in gas and dust are seen around nearly all young stars, and we know that at least a third of the ones orbiting single stars form planets. Some of these planets end up being misaligned with the spin of the star, so we've been wondering whether a similar thing might be possible for circumbinary planets. A quirk of the dynamics means that a so-called polar misalignment should be possible, but until now we had no evidence of misaligned discs in which these planets might form."Dr Kennedy and his fellow researchers used ALMA to pin down the orientation of the ring of gas and dust in the system. The orbit of the binary was previously known, from observations that quantified how the stars move in relation to each other. By combining these two pieces of information they were able to establish that the dust ring was consistent with a perfectly polar orbit.This means that while the stellar orbits orbit each other in one plane, like two horses going around on a carousel, the disc surrounds these stars at right angles to their orbits, like a giant ferris wheel with the carousel at the centre.Dr Grant M. Kennedy of the University of Warwick added: "Perhaps the most exciting thing about this discovery is that the disc shows some of the same signatures that we attribute to dust growth in discs around single stars. We take this to mean planet formation can at least get started in these polar circumbinary discs. If the rest of the planet formation process can happen, there might be a whole population of misaligned circumbinary planets that we have yet to discover, and things like weird seasonal variations to consider."If there were a planet or planetoid present at the inner edge of the dust ring, the ring itself would appear from the surface as a broad band rising almost perpendicularly from the horizon. The polar configuration means that the stars would appear to move in and out of the disc plane, giving objects two shadows at times.Seasons on planets in such systems would also be different. On Earth they vary throughout the year as we orbit the Sun. A polar circumbinary planet would have seasons that also vary as different latitudes receive more or less illumination throughout the binary orbit.Co-author Dr Daniel Price of Monash University's Centre for Astrophysics (MoCA) and School of Physics and Astronomy added: "We used to think other solar systems would form just like ours, with the planets all orbiting in the same direction around a single sun. But with the new images we see a swirling disc of gas and dust orbiting around two stars. It was quite surprising to also find that that disc orbits at right angles to the orbit of the two stars."Incredibly, two more stars were seen orbiting that disc. So if planets were born here there would be four suns in the sky!"ALMA is just a fantastic telescope, it is teaching us so much about how planets in other solar systems are born."The research is supported by the Monash Warwick Alliance, established by the University of Warwick and Monash University in 2012 as a bold and innovative project to develop an Alliance with a breadth, scale and impact beyond standard practice in the sector.Research Report: "A circumbinary protoplanetary disc in a polar configuration" in Nature Astronomy, DOI: 10.1038/s41550-018-0667-x
First comprehensive, interactive tool to track SETI searches
Donnerstag, 17.01.2019, 01:29:56 Uhr
Mountain View CA (SPX) Jan 10, 2019 -
For the first time ever, scientists have developed a way for the SETI community to keep track of, and update, all SETI searches that have been conducted and the results.Jill Tarter, SETI pioneer and co-founder of the SETI Institute, has launched Technosearch, a new-web-based tool that includes all published SETI searches from 1960 until the present. The tool also allows users to submit their own searches and keep the database current.According to Jill Tarter, "I started keeping this search archive when I was a graduate student. Some of the original papers were presented at conferences, or appear in obscure journals that are difficult for newcomers to the SETI field to access. I'm delighted that we now have a tool that can be used by the entire community and a methodology for keeping it current."Tarter developed Technosearch in collaboration with former Research Experience for Undergraduates (REU) interns, graduate students working with Professor Jason Wright at Penn State University and Andrew Garcia, SETI Institute 2018 REU student.Andrew Garcia said, "I started helping Dr. Tarter with this project as a research opportunity during the summer. I've become convinced that Technosearch will become an important instrument for astronomers and amateurs interested in exploring the cosmos for indications of other technological civilizations."We can't know where to look for evidence tomorrow if we don't know where we have already looked. Technosearch will help us chronicle where and how we've looked at the sky. I would like to thank the NSF REU program and the CAMPARE program for their encouragement and support throughout this project."Technosearch tracks information including:
Title of the search paper Name(s) of observers Search date Objects observed Facility where the search was conducted Size and sensitivity of the telescope used Resolving power of the instrument Time spent observing each object A link to the original published research paper Comments that explain the search strategy Observer notesTechnosearch includes sections for both radio and optical SETI. Currently this tool holds 102 Radio searches and 38 Optical searches, for a total of 140 different explorations.Moving forward, it is hoped that the SETI community will collaborate to keep Technosearch up-to-date and accurate.Since Frank Drake's very first SETI search in 1960, professional and amateur astronomers around the world have been searching and hoping to find evidence of life, especially intelligent life, beyond Earth.One significant challenge for the SETI community has been keeping track of the hundreds of searches that have already been conducted. Technosearch should address this problem.
Nature's magnifying glass reveals unexpected intermediate mass exoplanets
Donnerstag, 17.01.2019, 01:29:56 Uhr
Maunakea HI (SPX) Jan 09, 2019 -
Astronomers have found a new exoplanet that could alter the standing theory of planet formation. With a mass that's between that of Neptune and Saturn, and its location beyond the "snow line" of its host star, an alien world of this scale was supposed to be rare.Aparna Bhattacharya, a postdoctoral researcher from the University of Maryland and NASA's Goddard Space Flight Center (GSFC), led the team that made the discovery, which was announced during a press conference at the 233rd Meeting of the American Astronomical Society in Seattle.Using the Near-Infrared Camera, second generation (NIRC2) instrument on the 10-meter Keck II telescope of the W. M. Keck Observatory on Maunakea, Hawaii and the Wide Field Camera 3 (WFC3) instrument on the Hubble Space Telescope, the researchers took simultaneous high-resolution images of the exoplanet, named OGLE-2012-BLG-0950Lb, allowing them to determine its mass."We were surprised to see the mass come out right in the middle of the predicted intermediate giant planet mass gap," said Bhattacharya. "It's like finding an oasis in the middle of the exoplanet desert!""I was very pleased with how quickly Aparna completed the analysis," said co-author David Bennett, a senior research scientist at the University of Maryland and GSFC. "She had to develop some new methods to analyze this data - a type of analysis that had never been done before."In an uncanny timing of events, another team of astronomers (which included Bhattacharya and Bennett) published a statistical analysis at almost the same time showing that such sub-Saturn mass planets are not rare after all."We were just finishing up the analysis when the mass measurements of OGLE-2012- BLG-0950Lb came in," said lead author Daisuke Suzuki of Japan's Institute of Space and Astronautical Science. "This planet confirmed our interpretation of the statistical study."The teams' results on OGLE-2012-BLG-0950Lb are published in the December issue of The Astronomical Journal and the statistical study was published in the December 20th issue of the Astrophysical Journal Letters.OGLE-2012-BLG-0950Lb was among the sub-Saturn planets in the statistical study; all were detected through microlensing, the only method currently sensitive enough to detect planets with less than Saturn's mass in Jupiter-like orbits.Microlensing leverages a consequence of Einstein's theory of general relativity: the bending and magnification of light near a massive object like a star, producing a natural lens on the sky. In the case of OGLE-2012-BLG-0950Lb, the light from a distant background star was magnified by OGLE-2012-BLG-0950L (the exoplanet's host star) over the course of two months as it passed close to perfect alignment in the sky with the background star.By carefully analyzing the light during the alignment, an unexpected dimming with a duration of about a day was observed, revealing the presence of OGLE-2012-BLG-0950Lb via its own influence on the lensing.Methodology
OGLE-2012-BLG-0950Lb was first detected by the microlensing survey telescopes of the Optical Gravitational Lensing Experiment (OGLE) and the Microlensing Observations in Astrophysics (MOA) collaborations.Bhattacharya's team then conducted follow-up observations using Keck Observatory's powerful adaptive optics system in combination with NIRC2."The Keck observations allowed us to determine that the sub-Saturn or super-Neptune size planet has a mass of 39 times that of the Earth, and that its host star is 0.58 times the mass of the Sun," said Bennett. "They measured the separation of the foreground planetary system from the background star. This allowed us to work out the complete geometry of the microlensing event. Without this data, we only knew the star-planet mass ratio, not the individual masses."For the statistical study, Suzuki's team and MOA analyzed the properties of 30 sub-Saturn planets found by microlensing and compared them to predictions from the core accretion theory.Challenging The Theory
What is unique about the microlensing method is its sensitivity to sub-Saturn planets like OGLE-2012-BLG-0950Lb that orbit beyond the "snow line" of their host stars.The snow line, or frost line, is the distance in a young solar system, (a.k.a. a protoplanetary disk) at which it is cold enough for water to condense into ice. At and beyond the snow line there is a dramatic increase in the amount of solid material needed for planet formation. According to the core accretion theory, the solids are thought to build up into planetary cores first through chemical and then gravitational processes."A key process of the core accretion theory is called "runaway gas accretion," said Bennett."Giant planets are thought to start their formation process by collecting a core mass of about 10 times the Earth mass in rock and ice. At this stage, a slow accretion of hydrogen and helium gas begins until the mass has doubled. Then, the accretion of hydrogen and helium is expected to speed up exponentially in this runaway gas accretion process. This process stops when the supply is exhausted. If the supply of gas is stopped before runaway accretion stops, we get "failed Jupiter" planets with masses of 10-20 Earth-masses (like Neptune)."The runaway gas accretion scenario of the core accretion theory predicts that planets like OGLE-2012- BLG-0950Lb are expected to be rare. At 39 times the mass of the Earth, planets this size are thought to be continuing through a stage of rapid growth, ending in a much more massive planet. This new result suggests that the runaway growth scenario may need revision.Suzuki's team compared the distribution of planet-star mass ratios found by microlensing to distributions predicted by the core accretion theory.They found that the core accretion theory's runaway gas accretion process predicts about 10 times fewer intermediate mass giant planets like OGLE-2012- BLG-0950Lb than are seen in the microlensing results.This discrepancy implies that gas giant formation may involve processes that have been overlooked by existing core accretion models, or that the planet forming environment varies considerably as a function of host star mass.Next Steps
This discovery has not only called into question an established theory, it was made using a new technique that will be a key part of NASA's next big planet finding mission, the Wide Field Infra-Red Survey Telescope (WFIRST), which is scheduled to launch into orbit in the mid-2020s."This is exactly the method that WFIRST will use to measure the masses of the planets that it discovers with its exoplanet microlensing survey. Until WFIRST comes online, we need to develop this method with observations from our Keck Key Strategic Mission Support (KSMS) program as well as observations from Hubble," said Bennett."It's very exciting to see Keck and Hubble combine forces to provide this surprising new result," said Keck Observatory Chief Scientist John O'Meara. "And it's equally exciting to know that we can make these kind of advances today to help facilitate the best science from WFIRST and Keck's partnership in the future."The NASA Keck KSMS program will continue to make follow-up observations of microlensing events detected by telescopes on the ground and in space.
Potential for life on planet around Barnard's Star
Donnerstag, 17.01.2019, 01:29:56 Uhr
Villanova PA (SPX) Jan 11, 2019 -
Barnard b (or GJ 699 b) is a recently discovered Super-Earth planet orbiting Barnard's Star, making it the second nearest star system to the Earth. Although likely cold (-170 degrees centigrade), it could still have the potential to harbor primitive life if it has a large, hot iron/nickel core and enhanced geothermal activity.That was a conclusion announced by Villanova University Astrophysicists Edward Guinan and Scott Engle at a January 10 press conference held at the 223rd meeting of the American Astronomy Society (AAS) in Seattle, WA.The announcement was based on findings from a paper titled, "X-Ray, UV, Optical Irradiances and Age of Barnard's Star's New Super Earth Planet - 'Can Life Find a Way' on such a Cold Planet?", co-authored by Guinan, Scott Engle and Ignasi Ribas, Director of the Institute of Space Studies of Catalonia (IEEC), and Institute of Space Sciences (ICE, CSIC)."Geothermal heating could support "life zones" under its surface, akin to subsurface lakes found in Antarctica," Guinan said. "We note that the surface temperature on Jupiter's icy moon Europa is similar to Barnard b but, because of tidal heating, Europa probably has liquid oceans under its icy surface."The discovery of Barnard's Star b was announced in November 2018 in the academic journal Nature. An international team of researchers led by Ribas of the Institute of Space Studies of Catalonia (IEEC), and Institute of Space Sciences (ICE, CSIC), which included Guinan and Engle, based its analysis on 18 years of observations combined with newly acquired data.Barnard's Star b, with a mass just over three times that of the Earth, orbits Barnard's Star, a red dwarf star, every 233 days and at roughly the same distance that Mercury orbits the Sun. It passes near the dim star's snow line.Guinan and Engle have obtained high-precision photometry of Barnard's Star (as well as dozens of other stars) for the past 15 years. This data, along with that of other observers, was included in a recent comprehensive study led by Borja Toledo-Padron, a doctoral student at the Institute of Astrophysics of the Canary Islands, University of La Laguna. Although very faint, it may be possible for Barnard b to be imaged by future very large telescopes, according to Guinan."Such observations will shed light on the nature of the planet's atmosphere, surface, and potential habitability," he added."Barnard's Star has been on our radar for a long time," Guinan said. "In 2003 it became a founding star member of the Villanova 'Living with a Red Dwarf' program that has been sponsored by the National Science Foundation/National Aeronautical and Space Administration (NASA)."The most significant aspect of the discovery of Barnard's star b is that the two nearest star systems to the Sun are now known to host planets. This supports previous studies based on Kepler Mission data, inferring that planets can be very common throughout the galaxy, even numbering in the tens of billions," Engle noted."Also, Barnard's Star is about twice as old as the Sun - about 9 billion years old compared to 4.6 billion years for the Sun. The universe has been producing Earth-size planets far longer than we, or even the Sun itself, have existed."
TESS discovers its third new planet, with longest orbit yet
Donnerstag, 17.01.2019, 01:29:56 Uhr
Boston MA (SPX) Jan 08, 2019 -
NASA's Transiting Exoplanet Survey Satellite, TESS, has discovered a third small planet outside our solar system, scientists announced this week at the annual American Astronomical Society winter meeting in Seattle.The new planet, named HD 21749b, orbits a bright, nearby dwarf star about 53 light-years away, in the constellation Reticulum, and appears to have the longest orbital period of the three planets so far identified by TESS. HD 21749b journeys around its star in a relatively leisurely 36 days, compared to the two other planets - Pi Mensae b, a "super-Earth" with a 6.3-day orbit, and LHS 3844b, a rocky world that speeds around its star in just 11 hours. All three planets were discovered in the first three months of TESS observations.The surface of the new planet is likely around 300 degrees Fahrenheit - relatively cool, given its proximity to its star, which is almost as bright as the Sun."It's the coolest small planet that we know of around a star this bright," says Diana Dragomir, a postdoc in MIT's Kavli Institute for Astrophysics and Space Research, who led the new discovery. "We know a lot about atmospheres of hot planets, but because it's very hard to find small planets that orbit farther from their stars, and are therefore cooler, we haven't been able to learn much about these smaller, cooler planets. But here we were lucky, and caught this one, and can now study it in more detail."The planet is about three times the size of Earth, which puts it in the category of a "sub-Neptune." Surprisingly, it is also a whopping 23 times as massive as the Earth. But it is unlikely that the planet is rocky and therefore habitable; it's more likely made of gas, of a kind that is much more dense than the atmospheres of either Neptune or Uranus."We think this planet wouldn't be as gaseous as Neptune or Uranus, which are mostly hydrogen and really puffy," Dragomir says. "The planet likely has a density of water, or a thick atmosphere."Serendipitously, the researchers have also detected evidence of a second planet, though not yet confirmed, in the same planetary system, with a shorter, 7.8-day orbit. If it is confirmed as a planet, it could be the first Earth-sized planet discovered by TESS.In addition to presenting their results at the AAS meeting, the researchers have submitted a paper to Astrophysical Journal Letters."Something There"
Since it launched in April 2018, TESS, an MIT-led mission, has been monitoring the sky, sector by sector, for momentary dips in the light of about 200,000 nearby stars. Such dips likely represent a planet passing in front of that star.The satellite trains its four onboard cameras on each sector for 27 days, taking in light from the stars in that particular segment before shifting to view the next one. Over its two-year mission, TESS will survey nearly the entire sky by monitoring and piecing together overlapping slices of the night sky. The satellite will spend the first year surveying the sky in the Southern Hemisphere, before swiveling around to take in the Northern Hemisphere sky.The mission has released to the public all the data TESS has collected so far from the first three of the 13 sectors that it will monitor in the southern sky. For their new analysis, the researchers looked through this data, collected between July 25 and Oct. 14.Within the sector 1 data, Dragomir identified a single transit, or dip, in the light from the star HD 21749. As the satellite only collects data from a sector for 27 days, it's difficult to identify planets with orbits longer than that time period; by the time a planet passes around again, the satellite may have shifted to view another slice of the sky.To complicate matters, the star itself is relatively active, and Dragomir wasn't sure if the single transit she spotted was a result of a passing planet or a blip in stellar activity. So she consulted a second dataset, collected by the High Accuracy Radial velocity Planet Searcher, or HARPS, a high-precision spectrograph installed on a large ground-based telescope in Chile, which identifies exoplanets by their gravitational tug on their host stars."They had looked at this star system a decade ago and never announced anything because they weren't sure if they were looking at a planet versus the activity of the star," Dragomir says. "But we had this one transit, and knew something was there."Stellar Detectives
When the researchers looked through the HARPS data, they discovered a repeating signal emanating from HD 21749 every 36 days. From this, they estimated that, if they indeed had seen a transit in the TESS data from sector 1, then another transit should appear 36 days later, in data from sector 3. When that data became publicly available, a momentary glitch created a gap in the data just at the time when Dragomir expected the second transit to occur."Because there was an interruption in data around that time, we initially didn't see a second transit, and were pretty disappointed," Dragomir recalls. "But we re-extracted the data and zoomed in to look more carefully, and found what looked like the end of a transit."She and her colleagues compared the pattern to the first full transit they had originally discovered, and found a near perfect match - an indication that the planet passed again in front of its star, in a 36-day orbit."There was quite some detective work involved, and the right people were there at the right time," Dragomir says. "But we were lucky and we caught the signals, and they were really clear."They also used data from the Planet Finder Spectrograph, an instrument installed on the Magellan Telescope in Chile, to further validate their findings and constrain the planet's mass and orbit.Once TESS has completed its two-year monitoring of the entire sky, the science team has committed to delivering information on 50 small planets less than four times the size of Earth to the astronomy community for further follow-up, either with ground-based telescopes or the future James Webb Space Telescope."We've confirmed three planets so far, and there are so many more that are just waiting for telescope and people time to be confirmed," Dragomir says. "So it's going really well, and TESS is already helping us to learn about the diversity of these small planets."Research Report: "The Longest Period TESS Planet Yet: A Sub-Neptune Transiting a Bright, Nearby K Dwarf Star," Diana Dragomir et al., 2019, submitted to Astrophysical Journal Letters
Astronomers find warped protoplanetary disk around distant star
Donnerstag, 17.01.2019, 01:29:56 Uhr
Washington (UPI) Jan 8, 2019 -
Researchers in Japan have identified a young star with an already warped protoplanetary disk. The discovery could help scientists better understand how planets come to travel in slightly askew orbital planes.
Until now, astronomers assumed the sometimes off-kilter orbital planes of planets is caused by the gravitational influences of larger planets. In other words, the feature is acquired, not innate.
But using observations from the ALMA radio observatory in Chile, researchers at RIKEN located a warped disk around a protostar, L1527.
The star and its disk are enveloped in the thick gas of the Taurus Molecular Cloud some 450 light-years from Earth. Researchers were able to observe the infant star and its disk using far-infrared observations.
The ALMA data showed the star's disk can be divided into two parts. The inner and outer parts of the disk are orbiting in distinct planes.
"Warped disk structures have been reported in some transition disks and protoplanetary disks -- much elder than L1527 system -- but not in the earlier stages of protostar evolution," Nami Sakai, chief scientist at RIKEN's Star and Planet Formation Laboratory, told UPI.
Whether or not the protoplanetary disk is beginning to form planets depends on how planet formation is defined. Researchers measured changes in dust size, but can't confirm the aggregation of larger pebbles or rocks.
"Since L1527 disk is really young, still growing, still embedded in dense cloud, and just after the formation, even only the start of the dust-growth around the border of the inner and outer disk is surprising," Sakai said.
Researchers published their analysis of L1527 in the journal Nature.
Space microbes aren't so alien after all
Donnerstag, 17.01.2019, 01:29:56 Uhr
Evanston IL (SPX) Jan 09, 2019 -
Microbes stranded in the International Space Station (ISS) are just trying to survive, man.A new Northwestern University study has found that - despite its seemingly harsh conditions - the ISS is not causing bacteria to mutate into dangerous, antibiotic-resistant superbugs.While the team found that the bacteria isolated from the ISS did contain different genes than their Earthling counterparts, those genes did not make the bacteria more detrimental to human health. The bacteria are instead simply responding, and perhaps evolving, to survive in a stressful environment."There has been a lot of speculation about radiation, microgravity and the lack of ventilation and how that might affect living organisms, including bacteria," said Northwestern's Erica Hartmann, who led the study. "These are stressful, harsh conditions. Does the environment select for superbugs because they have an advantage? The answer appears to be 'no.'"The study was published Jan. 8 in the journal mSystems. Hartmann is an assistant professor of environmental engineering in Northwestern's McCormick School of Engineering.As the conversation about sending travelers to Mars gets more serious, there has been an increasing interest in understanding how microbes behave in enclosed environments."People will be in little capsules where they cannot open windows, go outside or circulate the air for long periods of time," said Hartmann. "We're genuinely concerned about how this could affect microbes."The ISS houses thousands of different microbes, which have traveled into space either on astronauts or in cargo. The National Center for Biotechnology Information maintains a publicly available database, containing the genomic analyses of many of bacteria isolated from the ISS. Hartmann's team used that data to compare the strains of Staphylococcus aureus and Bacillus cereus on the ISS to those on Earth.Found on human skin, S. aureus contains the tough-to-treat MRSA strain. B. cereus lives in soil and has fewer implications for human health."Bacteria that live on skin are very happy there," Hartmann said. "Your skin is warm and has certain oils and organic chemicals that bacteria really like. When you shed those bacteria, they find themselves living in a very different environment. A building's surface is cold and barren, which is extremely stressful for certain bacteria."To adapt to living on surfaces, the bacteria containing advantageous genes are selected for or they mutate. For those living on the ISS, these genes potentially helped the bacteria respond to stress, so they could eat, grow and function in a harsh environment."Based on genomic analysis, it looks like bacteria are adapting to live - not evolving to cause disease," said Ryan Blaustein, a postdoctoral fellow in Hartmann's laboratory and the study's first author. "We didn't see anything special about antibiotic resistance or virulence in the space station's bacteria."Although this is good news for astronauts and potential space tourists, Hartmann and Blaustein are careful to point out that unhealthy people can still spread illness on space stations and space shuttles."Everywhere you go, you bring your microbes with you," Hartmann said. "Astronauts are exceedingly healthy people. But as we talk about expanding space flight to tourists who do not necessarily meet astronaut criteria, we don't know what will happen. We can't say that if you put someone with an infection into a closed bubble in space that it won't transfer to other people. It's like when someone coughs on an airplane, and everyone gets sick."Research paper
Young planets orbiting red dwarfs may lack ingredients for life
Donnerstag, 17.01.2019, 01:29:56 Uhr
Baltimore MD (SPX) Jan 09, 2019 -
Rocky planets orbiting red dwarf stars may be bone dry and lifeless, according to a new study using NASA's Hubble Space Telescope (http://www.nasa.gov/hubble). Water and organic compounds, essential for life as we know it, may get blown away before they can reach the surface of young planets.This hypothesis is based on surprising observations of a rapidly eroding dust-and-gas disk encircling the young, nearby red dwarf star AU Microscopii (AU Mic) by Hubble and the European Southern Observatory's Very Large Telescope (VLT) in Chile. Planets are born in disks like this one.Red dwarfs, which are smaller and fainter than our Sun, are the most abundant and longest-lived stars in the galaxy.Fast-moving blobs of material appear to be ejecting particles from the AU Mic disk. If the disk continues to dissipate at this rapid pace, it will be gone in about 1.5 million years. In that short time, icy material from comets and asteroids could be cleared out of the disk.Comets and asteroids are important because they are believed to have seeded rocky planets such as Earth with water and organic compounds, the chemical building blocks for life. If this same transport system is needed for planets in the AU Mic system, then they may end up "dry" and dusty - inhospitable for life as we know it."The Earth, we know, formed 'dry,' with a hot, molten surface, and accreted atmospheric water and other volatiles for hundreds of millions of years, being enriched by icy material from comets and asteroids transported from the outer solar system," said co-investigator Glenn Schneider of Steward Observatory in Tucson, Arizona.The observations are led by John Wisniewski of the University of Oklahoma in Norman, whose team is composed of 14 astronomers from the U.S. and Europe.If the activity around AU Mic is typical of the planet-birthing process among red dwarfs, it could further reduce prospects of habitable worlds across our galaxy. Previous observations suggest that a torrent of ultraviolet light from young red dwarf stars quickly strips away the atmosphere of any orbiting planets. This particular star is only 23 million years old.Surveys have shown that terrestrial planets are common around red dwarfs. In fact, they should contain the bulk of our galaxy's planet population, which could number tens of billions of worlds. Planets have been found within the habitable zone of several nearby red dwarfs, but their physical characteristics are largely unknown.Blown Out by Blobs
Observations by Hubble's Space Telescope Imaging Spectrograph (STIS) and the VLT show that the AU Mic circumstellar disk is being excavated by fast-moving blobs of circumstellar material, which are acting like a snowplow by pushing small particles - possibly containing water and other volatiles - out of the system. Researchers don't yet know how the blobs were launched. One theory is that powerful mass ejections from the turbulent star expelled them. Such energetic activity is common among young red dwarfs."These observations suggest that water-bearing planets might be rare around red dwarfs because all the smaller bodies transporting water and organics are blown out as the disk is excavated," explained Carol Grady of Eureka Scientific in Oakland, California, co-investigator on the Hubble observations.Conventional theory holds that billions of years ago Earth formed as a comparatively dry planet. Gravitationally perturbed asteroids and comets, rich in water from the cooler outer solar system, bombarded Earth and seeded the surface with ice and organic compounds. "However, this process may not work in all planetary systems," Grady said.The team determined the disk's lifespan by using an estimated mass of the disk from an independent study, as well as calculating the mass of the escaping blobs in their STIS visible-light data. The mass of each blob is about four ten-millionths the mass of Earth. The disk's mass - about 1.7 times more massive than Earth - is based on data taken by the Atacama Large Millimeter/submillimeter Array (ALMA).Although the mass of the wayward blobs seems tiny, the diameter of each blob could stretch at least from the Sun to Jupiter. At present, the team has spotted six outbound blobs, but it is possible that there is a continuous stream of them. Groups of blobs careening through the disk could sweep out material fairly quickly."The fast dissipation of the disk is not something I would have expected," Grady said. "Based on the observations of disks around more luminous stars, we had expected disks around fainter red dwarf stars to have a longer time span. In this system, the disk will be gone before the star is 25 million years old." She added that AU Mic likely started out with an outer rim of small icy bodies, like the Kuiper belt found within our own solar system. If the disk weren't being eroded, it would have provided ices to any dry inner planets.Probing the Blob Mystery
Hubble astronomers spotted the blobs in STIS visible-light images taken in 2010-2011. As a follow-up to the Hubble study, the SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument mounted on the European Southern Observatory's Very Large Telescope in Chile, made near-infrared observations. Features in the disk were hinted at in observations taken in 2004 by ground-based telescopes and Hubble's Advanced Camera for Surveys.So far, the team has uncovered blobs on the disk's southeast side, with estimated ejection speeds between 9,000 miles per hour and 27,000 miles per hour, fast enough to escape the star's gravitational clutches. They currently range in distance from roughly 930 million miles to more than 5.5 billion miles from the star.Hubble is also showing that these blobs may not just be giant balls of dusty debris. The telescope has resolved substructure in one of the blobs, including a mushroom-shaped cap above the plane of the disk itself and a complex "loop-like" structure below the disk. "These structures could yield clues to the mechanisms that drive these blobs," Schneider said.The system resides 32 light-years away in the southern constellation Microscopium."AU Mic is ideally placed," Schneider said. "But it is only one of about three or four red-dwarf systems with known starlight-scattering disks of circumstellar debris. The other known systems are typically about six times farther away, so it's challenging to conduct a detailed study of the types of features in those disks that we see in AU Mic."However, astronomers are beginning to identify some possibly similar activity in these other systems. "It shows that AU Mic is not unique," Grady said. "In fact, you could argue that because it is one of the nearest systems of this type, it would be unlikely that it would be unique."The AU Mic observations show the importance of a star's disk environment on planet formation and evolution. "What we have learned is that disks seem to be a normal part of the history of planetary systems," Grady said. "If you don't understand a star's disk, you don't have a good understanding of the resulting planetary system."Grady is presenting the team's results at a press conference Jan. 8, at the 233rd meeting of the American Astronomical Society [https://aas.org/meetings/aas233] in Seattle, Washington.Research Report: "Observations of Fast-Moving Features in the Debris Disk of AU Mic on a Three-Year Timescale: Confirmation and New Discoveries," A. Boccaletti et al., 2018 June, Astronomy and Astrophysics
Citizen scientists find unusual exoplanet among Kepler data
Donnerstag, 17.01.2019, 01:29:56 Uhr
Washington (UPI) Jan 8, 2019 -
Citizen scientists have discovered an exoplanet twice the size of Earth located 226 light-years from Earth. The exoplanet's signature was discovered among data collected by NASA's Kepler space telescope.
The alien world, named K2-288Bb, is roughly twice the size of Earth, but scientists aren't certain whether it's composed of rock or is a mostly gaseous world, like Neptune. The exoplanet orbits a pair cool stars found within the Taurus constellation, both smaller and dimmer than the sun. The duo are separated by 5.1 billion miles.
"It's a very exciting discovery due to how it was found, its temperate orbit and because planets of this size seem to be relatively uncommon," Adina Feinstein, a University of Chicago graduate student who aided the discovery of K2-288Bb, said in a news release.
Kepler ran out of fuel last year, but algorithms, scientists and citizen scientists continue to scan its massive dataset for dimming patterns created by exoplanet transits.
Scientists found two transit signatures among data collected during the fourth observing campaign of Kepler's K2 mission, but they were unable to locate a third. Three transits are needed to confirm an exoplanet candidate.
But researchers hadn't seen all the data. During Kepler's K2 phase, the spacecraft's reorienting process introduced data anomalies that forced researchers to ignore the first few days of observations during each new campaign.
Only later did NASA scientists develop techniques to adjust for the anomalies.
"We eventually re-ran all data from the early campaigns through the modified software and then re-ran the planet search to get a list of candidates, but these candidates were never fully visually inspected," said Joshua Schlieder, an astrophysicist at NASA's Goddard Space Flight Center. "Inspecting, or vetting, transits with the human eye is crucial because noise and other astrophysical events can mimic transits."
Never examined by scientists, the re-processed data was relinquished to the citizen science project Exoplanet Explorers. Participating amateur astronomers located the third transit scientists were looking for, confirming the presence of K2-288Bb.
"It took the keen eyes of citizen scientists to make this extremely valuable find and point us to it," Feinstein said.
Scientists described the newly discovered exoplanet this week in the Astronomical Journal.