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  • Researchers discover a system with three Earth-sized planets
    Donnerstag, 14.06.2018, 00:05:59 Uhr
    Researchers discover a system with three Earth-sized planets La Laguna, Spain (SPX) Jun 11, 2018 -
    The information about these new exoplanets has been obtained from the data collected by the K2 mission of NASA's Kepler satellite, which started in November 2013. The work, which will be published in the Monthly Notices of the magazine Royal Astronomical Society (MNRAS), reveals the existence of two new planetary systems detected from the eclipses they produce in the stellar light of their respective stars.In the research team led jointly by Javier de Cos at the University of Oviedo, and Rafael Rebolo at the IAC, participate, along with researchers from these two centres, others from the University of Geneva and the Gran Telescopio Canarias (GTC).The first exoplanetary system is located in the star K2-239, characterized by these researchers as a red dwarf type M3V from observations made with the Gran Telescopio Canarias (GTC), at the Roque de los Muchachos Observatory (Garafia, La Palma).It is located in the constellation of the Sextant at 50 parsecs from the Sun (at about 160 light years). It has a compact system of at least three rocky planets of similar size to the Earth (1.1, 1.0 and 1.1 Earth radii) that orbit the star every 5.2, 7.8 and 10.1 days, respectively.The other red dwarf star called K2-240 has two super-Earth-like planets about twice the size of our planet. Although the atmospheric temperature of red dwarf stars, around which these planets revolve, is 3,450 and 3,800 K respectively, almost half the temperature of our Sun.These researchers estimate that all planets discovered will have temperatures superficial tens of degrees higher than those of the planet Earth due to the strong radiation they receive in these close orbits to their stars.Future observation campaigns with the new James Webb space telescope will characterize the composition of the atmospheres of the discovered planets. Spectroscopic observations with the ESPRESSO instrument, installed in the Very Large Telescope (VLT), of the European Southern Observatory (ESO), or with future spectrographs in the GTC or in new astronomical facilities, such as the ELT or the TMT, will be crucial to determine the masses, densities and physical properties of these planets.
  • Chandra Scouts Nearest Star System for Possible Hazards
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    Chandra Scouts Nearest Star System for Possible Hazards Boston MA (SPX) Jun 11, 2018 -
    In humanity's search for life outside our solar system, one of the best places scientists have considered is Alpha Centauri, a system containing the three nearest stars beyond our Sun.A new study that has involved monitoring of Alpha Centauri for more than a decade by NASA's Chandra X-ray Observatory provides encouraging news about one key aspect of planetary habitability.It indicates that any planets orbiting the two brightest stars in the Alpha Cen system are likely not being pummeled by large amounts of X-ray radiation from their host stars. X-rays and related space weather effects are bad for unprotected life, directly through high radiation doses and indirectly through stripping away planetary atmospheres (a fate thought to have been suffered by Mars in our own solar system).Alpha Centauri is a triple star system located just over four light-years, or about 25 trillion miles, from Earth. While this is a large distance in terrestrial terms, it is much closer than the next nearest Sun-like stars."Because it is relatively close, the Alpha Centauri system is seen by many as the best candidate to explore for signs of life," said Tom Ayres of the University of Colorado Boulder. "The question is, will we find planets in an environment conducive to life as we know it?"The stars in the Alpha Centauri system include a pair called "A" and "B," (AB for short) which orbit relatively close to each other. Alpha Cen A is a near twin of our Sun in almost every way, including age, while Alpha Cen B is somewhat smaller and dimmer but still quite similar to the Sun.The third member, Alpha Cen C (also known as Proxima), is a much smaller red dwarf star that travels around the AB pair in a much larger orbit that takes it more than 10 thousand times farther from the AB pair than the Earth-Sun distance. Proxima currently holds the title of the nearest star to Earth, although AB is a very close second.The Chandra data reveal that the prospects for life in terms of current X-ray bombardment are actually better around Alpha Cen A than for the Sun, and Alpha Cen B fares only slightly worse. Proxima, on the other hand, is a type of active red dwarf star known to frequently send out dangerous flares of X-ray radiation, and is likely hostile to life."This is very good news for Alpha Cen AB in terms of the ability of possible life on any of their planets to survive radiation bouts from the stars," said Ayres. "Chandra shows us that life should have a fighting chance on planets around either of these stars."While one remarkable Earth-size planet has been discovered around Proxima, astronomers continue to search, without success, for exoplanets around Alpha Cen A and B. Planet-hunting around these stars has proved more difficult recently due to the orbit of the pair, which has drawn the two bright stars close together on the sky over the past decade.To help determine whether Alpha Cen's stars are hospitable to life, astronomers have run a long-term campaign in which Chandra has observed the system's two main stars about every six months since 2005. Chandra is the only X-ray observatory capable of resolving AB during its current close orbital approach, to determine which star is doing what.These long-term measurements have captured the complete ups and downs of the X-ray activity of AB, analogous to the Sun's 11-year sunspot cycle. They show that any planets in the habitable zone for A would receive a lower dose of X-rays, on average, than similar planets around the Sun. For companion B the X-ray dose for habitable zone planets is higher than for the Sun, but only by a factor of about five.In comparison planets in the habitable zone around Proxima receive an average dose of X-rays about 500 times larger than the Earth, and 50,000 times larger during a big flare.Besides illuminating the possible habitability of Alpha Cen's planets, Chandra's X-ray history of AB plays into theoretical explorations of our own Sun's cyclical X-ray activity. Understanding this is a key to cosmic hazards such as space weather, which can impact the technology-laden civilization right here on our home world.Tom Ayres presented these results at the 232rd meeting of the American Astronomical Society meeting in Denver, Colorado, and some of these results were published in January 2018 in the Research Notes of the American Astronomical Society.Research paper
  • Study reveals simple chemical process that may have led to the origin of life on Earth
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    Study reveals simple chemical process that may have led to the origin of life on Earth Tokyo, Japan (SPX) Jun 14, 2018 -
    Research led by Kuhan Chandru and Jim Cleaves from the Earth-Life Science Institute at Tokyo Institute of Technology, Japan, has shown that reactions of alpha-hydroxy acids, similar to the alpha-amino acids that make up modern proteins, form large polymers easily under conditions presumed prevalent on early Earth. These alpha-hydroxy acid polymers may have aided in the formation of living systems on early Earth.There are different theories for how life first formed on early Earth. One popular one suggests that life may have arisen in specialized environments, such as tidal pools or shallow water hot springs, where simple chemical reactions would have helped generate life's precursors.All life is made up of polymers, large molecules made up of a sequence of molecules called monomers. A key question is how biological polymers could have formed without enzymes on early Earth.While environments of early Earth might have had monomers that could give rise to life, it would have been difficult for polymers to arise from these without the help of enzymes. In this case, the team showed these polymers could have formed with alpha-hydroxy acids before the existence of enzymes on early Earth.This multi-national team showed that hydroxy acids polymerize more easily than amino acids, and that they could have provided the necessary toolkit to kick-start the formation of more complex molecules for the origin of life on Earth.To simulate various primitive environments, the team reacted alpha hydroxy acids under varied conditions of pH and temperature, from room temperature to boiling hot. Using sophisticated high-resolution mass spectrometry and data analysis software, they showed that these polymers can form over a range of conditions.The team showed further, that using a mixture of different types of alpha-hydroxy acid that they could form huge numbers of types of polymers, in effect creating vast 'libraries' of different chemical structures, which can remain stable over a range of environmental conditions.The work culminated with the creation of a polyester library made up of five kinds of alpha hydroxy acids. They showed that this simple-to-create library could contain hundreds of trillions of distinct polymer sequences.This research opens new areas of exploration of the chemistry that may have led to the formation of life. The authors are keen to extend this work by investigating the types of functions of alpha-hydroxy acid polymers might be able to carry out, and other types of simple chemicals that could interact with these, possibly leading to self-replicating chemical systems.Research Report: Simple prebiotic synthesis of high diversity dynamic combinatorial polyester libraries
  • Researchers discover multiple alkali metals in unique exoplanet
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    Researchers discover multiple alkali metals in unique exoplanet La Laguna, Spain (SPX) Jun 08, 2018 -
    The extrasolar planet WASP-127b is one of the least dense exoplanets ever found. It has a radius 1.4 times greater than Jupiter, but only 20% of its mass. Such a planet has no analogue in the solar system and is rare even within the exoplanet diversity. It takes just over four days to complete an orbit around its parent star and its surface temperature is around 1400 K (1127 C).The observations of WASP-127b reveal the presence of a large concentration of alkali metals in its atmosphere, allowing simultaneous detections of Sodium, Potassium and Lithium, for the first time in an exoplanet. The Sodium and Potassium absorptions are very broad, which is a characteristic shape in relatively clear atmospheres, and model fits indicate that the skies of WASP-127b are approximately 50% clear.Guo Chen, a postdoctoral researcher at the IAC and first author of the article, explains "the particular characteristics of this planet allowed us to perform a detailed study of its rich atmospheric composition". And adds that "The presence of Li is very valuable to understand the evolutionary history of the planetary system and could shed light on the mechanisms of planet formation". In fact, the planet's host star, WASP-127, is also Li rich, which could point to an AGB star or supernovae having enriched the cloud of material from which this system originated.Enric Palle, a researcher at the IAC and co-author of the study, points out that they also found possible signs of water. "While this detection is not statistically significant, as water features are weak in the visible," he says, "our data indicates that additional observations in the near-infrared should detect it with high significance."The results obtained indicate the great potential of ground-based telescopes for the study of planetary atmospheres. "In particular, the detection of a trace element such as Li in a planetary atmosphere is a major breakthrough and motivates new follow-up observations and detailed theoretical modelling to corroborate the findings", says Nikku Madhusudhan, from the University of Cambridge.We are just starting to probe the atmospheres of these planets with ground-based telescopes, but Chen believes that this "will also be a reference exoplanet for future studies with space telescopes such as the James Webb." These future studies will reveal the detailed nature of WASP-127b as a benchmark for this new class of very low density exoplanets.The WASP-127b observations were conducted using the OSIRIS instrument of the GTC, from the Roque de los Muchachos Observatory, in Garafia (La Palma). The Observatories of the Instituto de Astrofisica de Canarias (IAC) and the Gran Telescopio CANARIAS (GTC) are part of the Spanish Unique Scientific and Technical Infrastructures (ICTS) network.Research paper
  • The Clarke exobelt, a method to search for possible extraterrestrial civilizations
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    The Clarke exobelt, a method to search for possible extraterrestrial civilizations La Laguna, Spain (SPX) Jun 08, 2018 -
    Finding life in other parts of the universe has been one of humanity's constant dreams. For the first time in history the scientific community has hopes based on some degree of possibility that this dream will become a reality in the not too distant future.This is, in part, due to the new generation of giant telescopes, presently in the planning phase, which we hope to be able to make a detailed analysis of the atmospheres of planets beyond the Solar System. For this reason researchers are making efforts to investigate "biomarkers", which is the term for observable evidence which we could use to give us firm evidence of life on these planets.However, one thing is to find some form of life, but another, very different, is to find intelligent civilizations, or technological capacity, which seems much less likely. To start with we don't know whom we are looking for, we lack "technomarkers" (the analogues of biomarkers, but which reveal the presence of technology). Since the 80's of the last century there have been searches for radio signals from other civilizations, so far unsuccessful.This is hardly surprising if we remember that the radio emissions from a society such as ours would not be detectable at interstellar distances, unless they were deliberately focused in the direction of the receiver. In the scientific literature there have been proposals to look for technomarkers, for instance the well known "Dyson Spheres" which would be hypothetical artificial megastructures constructed around a star to collect its light and thereby supply the need for energy of a civilization much more advanced than ours.In an article published today by the IAC researcher Hector Socas proposed a new technomarker, which is characterized by the fact that it could be produced by present day technology on Earth. There is a very interesting region in space around planets called the "Clarke Belt" in honour of Arthur C. Clarke who in 1945 published an article about the use of geostationary orbits for telecommunications. In this belt orbit the geostationary satellites which we use for a large number of practical applications.The publication presents a variety of simulations of "Clarke exobelts" to investigate what would be the imprint they would leave on the light of the parent star as the planet transits across its disk. The optimum conditions for observing them are found for planets in orbit round red dwarf stars, which are also the best places to look for exoplanets in general. In the article published in The Astrophysical Journal details are given of how these artificial belts can be distinguished from natural rings.Using this technique current projects and space missions designed to detect exoplanets and their moons and rings could also be used to detect this marker. "It is a search which we will have for nothing" says Hector Socas, and he adds "We have to keep our eyes open, just in case we detect this traces in the data".Humanity's Clarke Belt (our geostationary and geosynchronous satellites) is not densely populated enough to be detected at interstellar distances, at least with our present observing capabilities. Around two thirds of existing satellites are in the region termed "low orbit", which means the first few hundred kilometres above the Earth, where space debris is already a significant problem.The Clarke belt orbit is it 36,000 km above the Earth, and it is so far much less populated, but the article shows that during recent decades the density of satellites in these orbits has been growing exponentially. If this rate continues our Clarke belt would be detectable from other stars by the year 2200.The rate could even be speeded up if access to these orbits was reduced in cost, for example by the new reusable rockets, or by the construction of a future space lift. Or it could be slowed down if technological advance looked for other priorities. In any case there is an active debate about whether humanity should actively send messages into space or whether, on the contrary, we ought to listen discreetly without revealing our presence."In this context, the exponential increase in our population of satellites could end up by becoming a signal which gives us away, whether we like it or not. This is a point which should be taken into account in this debate" says Socas.Faced with the question of whether one day we will discover an "Clarke exobelt", and thereby find an extraterrestrial civilization, the researcher gives his vies that "It seems unlikely, but it costs nothing to take a look. It is as if someone gave you a lottery ticket. You know that it is very unlikely that you will win, but as you have it you check up on the result, just in case".Research paper
  • Searching for Potential Life-Hosting Planets Beyond Earth
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    Searching for Potential Life-Hosting Planets Beyond Earth Charlottesville VA (SPX) Jun 05, 2018 -
    In recent years, astronomers have discovered more than 4,000 exoplanets (and counting) - planets outside our solar system. The majority of those planets are Earth-sized, to about 2.5 times the size of Earth, and therefore considered to have the potential for facilitating the development of life.But which ones, specifically, could harbor organisms?One way to narrow the search for habitable planets is to determine which of the many planets that have been found possess magnetic fields. A magnetic field will shield whatever atmosphere it might have from particles (electrons or protons) emitted from its solar system's Sun, and an atmosphere is considered necessary for the development of life. Without a protective magnetic field, a planet may never develop an atmosphere, or its atmosphere will erode into space.Earth has a strong magnetic field, and is therefore able to maintain an atmosphere, essential to life as we know it. Mars, on the other hand, once had a strong magnetic field and an atmosphere that very possibly could have allowed conditions conducive to the development of some form of life, but it long ago lost its water to space due to the loss of its protective magnetic field, resulting now in conditions unlikely to support any form of life."One of the most elusive goals in exoplanet science today is the detection of exoplanetary magnetic fields," said Jake Turner, a University of Virginia Ph.D. candidate in astronomy. "Knowledge of the magnetic field of a planet is extremely important because it can help us determine what the interior of a planet might be, whether it could be rocky and have the potential to possess an atmosphere with water, conditions needed for life."Turner is developing novel techniques to detect radio emissions from exoplanets with magnetic fields. Such planets, which are dozens to hundreds of light-years away, will produce radio waves (as do all of the magnetized planets in our solar system - Mercury, Earth, Jupiter, Uranus and Neptune) that, though faint, likely could be detected from Earth by astronomers using specialized radio telescope techniques, such as the one Turner is developing.Turner is using Europe's Low-Frequency Array, called LOFAR, to measure radio waves emanating from Jupiter as a way to extrapolate how radio waves from very distant planets might be separated out from other background radio "noise."By using Jupiter, the largest planet in our solar system, as a proxy, Turner can scale the emissions to mimic those of exoplanets. It's a way to survey the skies to find a needle in a haystack."If we can get a handle on how to find direct radio emissions from large exoplanets, we can then eventually use these same techniques to study Earth-sized planets and determine which ones have magnetic fields. These magnetized Earth-sized planets would then be possible candidates to investigate further, looking for biological signatures, such as water vapor, in a search for life," he said."The goal is to determine up to what distance and with what strength radio emission from exoplanets can be seen using LOFAR."This is the first time, Turner said, that expected radio emission from exoplanets has been simulated using a real planetary signal (Jupiter's radio waves observed with LOFAR). He is presenting his findings Monday at the annual meeting of the American Astronomical Society in Denver.Later in June he will defend his Ph.D. thesis, which is on the Jupiter proxy technique and other exoplanet magnetic field and atmosphere research."The study demonstrates that radio bursts from an exoplanet located at 65 light-years from Earth, an area encompassing tens of known exoplanets, could be detected if the brightness of the signal is a million times stronger than the peak level of Jupiter's radio emission," Turner said."This finding is consistent with theoretical models that predict such strong radio emission can exist, and can be used as a guide to search for radio emission from exoplanets."While a brightness of a million times that of Jupiter would indicate a very large planet, Turner said, such a planet very possibly could have moons roughly the size of Earth, with their own magnetic fields.Research Report: "The Search for Radio Emission from Exoplanets Using LOFAR Beam-Formed Observations: Jupiter as an Exoplanet," Jake D. Turner et al., 2018, submitted to Astronomy and Astrophysics
  • How microbes survive clean rooms and contaminate spacecraft
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    How microbes survive clean rooms and contaminate spacecraft Pomona CA (SPX) Jun 03, 2018 -
    Spacecraft assembly facilities harbor a low but persistent amount of biological contamination despite the use of clean rooms.Rakesh Mogul, a Cal Poly Pomona professor of biological chemistry, was the lead author of an article in the journal Astrobiology that offers the first biochemical evidence explaining the reason the contamination persists.Chemistry professor Gregory A. Barding, Jr., was a collaborator and second author on the paper. The remaining 22 coauthors are all Cal Poly Pomona students - 14 undergraduates in chemistry, three chemistry graduate students and five undergraduates in biological sciences."We designed the project to give students hands-on experience - and to support the learn-by-doing philosophy of Cal Poly Pomona. The students did the research, mostly as thesis projects in the areas of enzymology, molecular microbiology and analytical chemistry," said Mogul.In the clean room facilities, NASA implements a variety of planetary protection measures to minimize biological contamination of spacecraft. These steps are important because contamination by Earth-based microorganisms could compromise life-detection missions by providing false positive results.Despite extensive cleaning procedures, however, molecular genetic analyses show that the clean rooms harbor a diverse collection of microorganisms, or a spacecraft microbiome, that includes bacteria, archaea and fungi, explained Mogul. The Acinetobacter, a genus of bacteria, are among the dominant members of the spacecraft microbiome.To figure out how the spacecraft microbiome survives in the cleanroom facilities, the research team analyzed several Acinetobacter strains that were originally isolated from the Mars Odyssey and Phoenix spacecraft facilities.They found that under very nutrient-restricted conditions, most of the tested strains grew on and biodegraded the cleaning agents used during spacecraft assembly. The work showed that cultures grew on ethyl alcohol as a sole carbon source while displaying reasonable tolerances towards oxidative stress. This is important since oxidative stress is associated with desiccating and high radiation environments similar to Mars.The tested strains were also able to biodegrade isopropyl alcohol and Kleenol 30, two other cleaning agents commonly used, with these products potentially serving as energy sources for the microbiome."We're giving the planetary protection community a baseline understanding of why these microorganisms remain in the clean rooms," said Mogul. "There's always stuff coming into the clean rooms, but one of the questions has been why do the microbes remain in the clean rooms, and why is there a set of microorganisms that are common to the clean rooms."For planetary protection, this indicates that more stringent cleaning steps may be needed for missions focused on life detection and highlights the potential need to use differing and rotating cleaning reagents that are compatible with the spacecraft to control the biological burden."Metabolism and Biodegradation of Spacecraft Cleaning Reagents by Strains of Spacecraft-Associated Acinetobacter," Rakesh Mogul et al., 2018 Apr. 19, Astrobiology
  • Sorry ET, Got Here First: Russian Scientist Suggests Humans Would Destroy Aliens
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    Sorry ET, Got Here First: Russian Scientist Suggests Humans Would Destroy Aliens Moscow (Sputnik) Jun 04, 2018 -
    The good news is that a prominent physicist has given a new solution to the question why no extraterrestrial life has yet been detected in the observable universe despite its high probability. The bad news is that his theory "predicts a future for our own civilization that is even worse than extinction," as he puts it.A prominent physicist from the National Research University of Electronic Technology (MIET), Alexander Berezin, has suggested that the "first in, last out" principle can resolve the so-called Ferma paradox. Over the last century, scientists have been bothered with a discrepancy: we haven't observed a technologically advanced extraterrestrial intelligence (ETI) in the universe, although under commonplace assumptions this absence is highly unlikely.Berezin has suggested a solution, trivial but hard to accept, in his own words. According to his "first in, last out" hypothesis, the first life, which rises to interstellar travel, necessarily eradicates all competition to fuel its own expansion. And the fact that we haven't still met any aliens could be evidence they haven't yet achieved our technological level.The basis for his assumption involves key characteristics of life, growth and reproduction. According to the scholar, "they provide an incentive for life to spread out of its original habitat, and, inevitably, out into space" - and this drive is strong.When independently arising beings meet during their cosmic expansion phase, the most developed one is expected to wipe out less intelligent life forms. Berezin points out that there's nothing personal or ill-willed about such a scenario."Most likely, they simply won't notice, the same way a construction crew demolishes an anthill to build real estate because they lack incentive to protect it," he states.The scientist gives an example that could be a scary sci-fi plot. According to him, it only takes one bad actor to ruin the equilibrium."One rogue AI can potentially populate the entire supercluster with copies of itself, turning every solar system into a supercomputer, and there is no use asking why it would do that. All that matters is that it can," his paper reads.According to Berezin, people are "first to arrive at the stage," considering that "our planet and star are still relatively intact, and we are already contemplating the first interstellar probes." And, taking his theory into account, we will be the last to leave.The question of space travel has long bothered the most brilliant human minds, even now as the first preparations are being made for human beings to colonize other planets. For example, one of the most eager advocates of colonizing Mars is the founder of SpaceX and Tesla, Elon Musk.In March he had announced that SpaceX's interplanetary spaceship could have its first test flight in the first half of 2019. He claims that his ultimate goal is to colonize Mars, securing a getaway for the human race in the event of a looming apocalyptic scenario.According to him, there is "some probability" of a new Dark Ages, "particularly if there is a third world war." And his project is said to aim at keeping "enough of a seed of human civilization somewhere else to bring civilization back."Source: Sputnik News
  • Planets Can Easily Exist in Triple Star Systems
    Donnerstag, 14.06.2018, 00:05:59 Uhr
    Planets Can Easily Exist in Triple Star Systems Johannesburg, South Africa (SPX) Jun 05, 2018 -
    Researchers from the University of the Witwatersrand in South Africa (Wits) and the University of Grenoble Alpes in France have mapped out regions where exoplanets can exist within triple star systems.The study, led by Franco Busetti, at the School of Computer Science and Applied Mathematics at Wits, shows that there are large stable areas where exoplanets can indeed exist in both binary and triple star systems. A binary star system is where two stars are in orbit around each other, while a triple system is when a third star orbits around both the stars in a binary system."Because of the complex dynamics between these stars and planets, it was previously thought improbable that many planets would have stable orbits in these regions," says Busetti.As part of his PhD, Busetti worked with Herve Beust of the Institute of Planetology and Astrophysics at the University of Grenoble Alpes in France, and Charis Harley at Wits. Together they ran over 45,000 high-performance computer simulations over a three-year period, examining all the possible combinations of orbits, dimensions, masses and other variables of a series of 24 different stellar combinations.They showed that it was indeed possible for exoplanets to exist within substantial regions of these systems. They also mapped out areas where it was most likely that these planets could be found."We ran the simulations for periods ranging from 1 million to 10 million years, in order to see if the systems are stable over very long periods. If a planet collides with a star or is ejected from that system during this time, it is not considered stable."Exoplanets are planets that exist outside of our solar system. Of the 3,700 exoplanets that have been found to date, less than 40 are in triple star systems. Busetti says this is because the discovery rate of triple systems has been low, but the new Gaia and TESS missions should find many more."The analysis shows that most configurations had large enough stable regions for planets to exist. Many of these areas are actually very habitable for planets."The research has been submitted for consideration to be published in the journal Astronomy and Astrophysics. The work could assist in guiding future observational campaigns to discover planets in triple star systems."It could assist in selecting suitable candidates for a survey of such systems and guide the observational searches for them," says Busetti. "The geometry of the stable zone indicates not only where to look for planets but how to look."The results can also be used by other astronomers to quickly determine the feasibility of their initial observations of exoplanet orbits.
  • Distant moons may harbor life
    Donnerstag, 14.06.2018, 00:05:59 Uhr
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    Distant moons may harbor life Riverside CA (SPX) Jun 01, 2018 -
    We've all heard about the search for life on other planets, but what about looking on other moons?In a paper forthcoming in The Astrophysical Journal, researchers at the University of California, Riverside and the University of Southern Queensland have identified more than 100 giant planets that potentially host moons capable of supporting life. Their work will guide the design of future telescopes that can detect these potential moons and look for tell-tale signs of life, called biosignatures, in their atmospheres.Since the 2009 launch of NASA's Kepler telescope, scientists have identified thousands of planets outside our solar system, which are called exoplanets. A primary goal of the Kepler mission is to identify planets that are in the habitable zones of their stars, meaning it's neither too hot nor too cold for liquid water - and potentially life - to exist.Terrestrial (rocky) planets are prime targets in the quest to find life because some of them might be geologically and atmospherically similar to Earth. Another place to look is the many gas giants identified during the Kepler mission. While not a candidate for life themselves, Jupiter-like planets in the habitable zone may harbor rocky moons, called exomoons, that could sustain life."There are currently 175 known moons orbiting the eight planets in our solar system. While most of these moons orbit Saturn and Jupiter, which are outside the Sun's habitable zone, that may not be the case in other solar systems," said Stephen Kane, an associate professor of planetary astrophysics and a member of the UCR's Alternative Earths Astrobiology Center. "Including rocky exomoons in our search for life in space will greatly expand the places we can look."The researchers identified 121 giant planets that have orbits within the habitable zones of their stars. At more than three times the radii of the Earth, these gaseous planets are less common than terrestrial planets, but each is expected to host several large moons.Scientists have speculated that exomoons might provide a favorable environment for life, perhaps even better than Earth. That's because they receive energy not only from their star, but also from radiation reflected from their planet. Until now, no exomoons have been confirmed."Now that we have created a database of the known giant planets in the habitable zone of their star, observations of the best candidates for hosting potential exomoons will be made to help refine the expected exomoon properties. Our follow-up studies will help inform future telescope design so that we can detect these moons, study their properties, and look for signs of life," said Michelle Hill, an undergraduate student at the University of Southern Queensland who is working with Kane and will join UCR's graduate program in the fall.The title of the paper is "Exploring Kepler Giant Planets in the Habitable Zone." In addition to Hill, who is the is lead author, and Kane, other contributors are: Eduardo Seperuelo Duarte from Instituto Federal do Rio de Janeiro in Brazil; Ravi K. Kopparapu from the NASA Goddard Flight Center in Maryland; Dawn M. Gelino from the NASA Exoplanet Science Institute at Caltech; and Robert A. Wittenmyer from University of Southern Queensland.Research paper
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