Tagged: Exoplanets Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 10:45 am on September 15, 2014 Permalink | Reply
    Tags: , , , , , , Exoplanets   

    From Astrobiology: “Planets with Oddball Orbits Like Mercury Could Host Life” 

    Astrobiology Magazine

    Astrobiology Magazine

    Sep 15, 2014
    Charles Q. Choi

    mercury
    On Mercury a solar day is about 176 Earth days long. During its first Mercury solar day in orbit the MESSENGER spacecraft imaged nearly the entire surface of Mercury to generate a global monochrome map at 250 meters per pixel resolution and a 1 kilometer per pixel resolution color map. Credit: NASA/JHU APL/CIW

    Mercury has an oddball orbit — it takes longer for it to rotate on its axis and complete a day than it takes to orbit the sun and complete a year. Now, researchers suggest photosynthesis could take place on an alien planet with a similarly bizarre orbit, potentially helping support complex life.

    However, the scientists noted that the threat of prolonged periods of darkness and cold on these planets would present significant challenges to life, and could even potentially freeze their atmospheres. They detailed their findings in the International Journal of Astrobiology.

    Astronomers have discovered more than 1,700 alien planets in the past two decades, raising the hope that at least some might be home to extraterrestrial life. Scientists mostly focus the search for alien life on exoplanets in the habitable zones of stars. These are regions where worlds would be warm enough to have liquid water on their surfaces, a potential boon to life.

    spin
    The 3:2 spin orbit resonance of Mercury and the Sun. Credit: Wikicommons

    Although many exoplanets are potentially habitable, they may differ from Earth significantly in one or more ways. For instance, habitable planets around dim red dwarf stars orbit much closer than Earth does to the Sun, sometimes even closer than Mercury’s distance. Red dwarfs are of interest as possible habitats for life because they are the most common stars in the universe — if life can exist around red dwarfs, then life might be very common across the cosmos. Recent findings from NASA’s Kepler Space Observatory suggest that at least half of all red dwarfs host rocky planets that are one-half to four times the mass of Earth.

    NASA Kepler Telescope
    NASA/Kepler

    Since a planet in the habitable zone of a red dwarf orbits very near its star, it experiences much stronger gravitational tidal forces than Earth does from the Sun, which slows the rate at which those worlds spin. The most likely result of this slowdown is that the planet enters what is technically called a 1:1 spin orbit resonance, completing one rotation on its axis every time it completes one orbit around its star. This rate of rotation means that one side of that planet will always face toward its star, while the other side will permanently face away, just as the Moon always shows the same side to Earth. One recent study suggests that such “tidally locked” planets may develop strange lobster-shaped oceans basking in the warmth of their stars on their daysides, while the nightsides of such worlds are mostly covered in an icy shell.

    However, if a habitable red dwarf planet has a very eccentric orbit — that is, oval-shaped — it could develop what is called a 3:2 spin orbit resonance, meaning that it rotates three times for every two orbits around its star. Mercury has such an unusual orbit, which can lead to strange phenomena. For instance, at certain times on Mercury, an observer could see the Sun rise about halfway and then reverse its course and set, all during the course of one mercurial day. Mercury itself is not habitable, since it lacks an atmosphere and experiences temperatures ranging from 212 to 1,292 degrees Fahrenheit (100 to 700 degrees Celsius).

    “If the Sun were less intense, Mercury would be within the habitable zone, and therefore life would have to adapt to strange light cycles,” said lead study author Sarah Brown, an astrobiologist at the United Kingdom Center for Astrobiology in Edinburgh, Scotland.

    Light is crucial for photosynthesis, the process by which plants and other photosynthetic organisms use the Sun’s rays to create energy-rich molecules such as sugars. Most life on Earth currently depends on photosynthesis or its byproducts in one way or the other, and while primitive life can exist without photosynthesis, it may be necessary for more complex multi-cellular organisms to emerge because the main source for oxygen on Earth comes from photosynthetic life, and oxygen is thought to be necessary for multi-cellular life to arise.

    To see what photosynthetic life might exist on a habitable red dwarf planet with an orbit similar to Mercury’s, scientists calculated the amount of light that reached all points on its surface. Their model involved a planet the same mass and diameter as the Earth with a similar atmosphere and amount of water on its surface. The red dwarf star was 30 percent the Sun’s mass and 1 percent as luminous, giving it a temperature of about 5,840 degrees Fahrenheit (3,225 degrees Celsius) and a habitable zone extending from 10 to 20 percent of an astronomical unit (AU) from the star. (One AU is the average distance between Earth and the Sun.)

    spin
    The 1:1 spin orbit resonance of Earth and the Moon. Credit: Wikicommons

    The scientists found that the amount of light the surface of these planets received concentrated on certain bright spots. Surprisingly, the amount of light these planets receive do not just vary over latitude as they do on Earth, where more light reaches equatorial regions than polar regions, but also varied over longitude. Were photosynthetic life to exist on worlds with these types of orbits, “one would expect to find niches that depend on longitude and latitude, rather than just latitude,” said study co-author Alexander Mead, a cosmologist at the Royal Observatory, Edinburgh, in Scotland.

    The research team found these planets could experience nights that last for months. This could pose major problems for photosynthetic life, which depends on light. Still, the scientists noted that many plants can store enough energy to last through 180 days of darkness. Moreover, some photosynthetic microbes spend up to decades dormant in the dark, while others are mixotrophic, which means they can survive on photosynthesis when light is abundant and switch to devouring food when light is absent.

    Another problem these long spans of darkness pose for life is the cold, which could freeze the atmospheres of these planets. Still, the investigators note that heat can flow from the dayside of such a planet to its nightside and prevent this freezing if that planet’s atmosphere is sufficiently dense and can trap infrared light from the planet’s star. This heat flow could lead to very strong winds, but this does not necessarily make the world uninhabitable, they added.

    “Life having to cope with such tidally driven resonances could be common in the universe,” Mead said. “It changes one’s perception of what habitable planets in the Universe would be like. There are many possibilities that are very un-Earth-like.”

    big
    It is difficult to form Mercury in solar system simulations, suggesting that some of our assumptions about the small planet’s formation might be wrong, a new study suggests. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

    However, the researchers noted that the strength of a world’s magnetic field depends in large part on how quickly it spins, which suggests that planets with orbits like Mercury’s might have relatively weak magnetic fields. This could mean these worlds are not as good at deflecting harmful electrically charged particles streaming from their red dwarfs and other stars that can damage organisms and strip off the atmospheres of these planets.

    The investigators suggested that dense atmospheres could help keep such planets habitable in the face of radiation from space. They added that life might be confined to certain spots on the surfaces of those planets that experience relatively safe levels of radiation.

    Are astronomers capable of detecting habitable planets with a 3:2 spin orbit resonance?

    “Measuring the day length of extrasolar planets is enormously difficult, and the first day length measurements for any extrasolar planets were only published this year,” Mead said. “Such a measurement for the planets we discuss would be much more difficult due to the fact that they are small, rocky planets around faint stars. This means that we are probably a long way from measuring the spin rates of such habitable worlds.”

    Another problem these long spans of darkness pose for life is the cold, which could freeze the atmospheres of these planets. Still, the investigators note that heat can flow from the dayside of such a planet to its nightside and prevent this freezing if that planet’s atmosphere is sufficiently dense and can trap infrared light from the planet’s star. This heat flow could lead to very strong winds, but this does not necessarily make the world uninhabitable, they added.

    “Life having to cope with such tidally driven resonances could be common in the universe,” Mead said. “It changes one’s perception of what habitable planets in the Universe would be like. There are many possibilities that are very un-Earth-like.”

    It is difficult to form Mercury in solar system simulations, suggesting that some of our assumptions about the small planet’s formation might be wrong, a new study suggests. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

    It is difficult to form Mercury in solar system simulations, suggesting that some of our assumptions about the small planet’s formation might be wrong, a new study suggests. NASA/Johns Hopkins University

    However, the researchers noted that the strength of a world’s magnetic field depends in large part on how quickly it spins, which suggests that planets with orbits like Mercury’s might have relatively weak magnetic fields. This could mean these worlds are not as good at deflecting harmful electrically charged particles streaming from their red dwarfs and other stars that can damage organisms and strip off the atmospheres of these planets.

    The investigators suggested that dense atmospheres could help keep such planets habitable in the face of radiation from space. They added that life might be confined to certain spots on the surfaces of those planets that experience relatively safe levels of radiation.

    Are astronomers capable of detecting habitable planets with a 3:2 spin orbit resonance?

    “Measuring the day length of extrasolar planets is enormously difficult, and the first day length measurements for any extrasolar planets were only published this year,” Mead said. “Such a measurement for the planets we discuss would be much more difficult due to the fact that they are small, rocky planets around faint stars. This means that we are probably a long way from measuring the spin rates of such habitable worlds.”

    See the full article here.

    NASA

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 8:35 pm on September 14, 2014 Permalink | Reply
    Tags: , , , , , , Exoplanets   

    From Astrobiology: “NASA Research Gives Guideline for Future Alien Life Search” 

    Astrobiology Magazine

    Astrobiology Magazine

    Sep 13, 2014
    At NASA
    William Steigerwald
    NASA’s Goddard Space Flight Center, Greenbelt, Maryland

    Gabriela Frias
    Universidad Nacional Autonoma de Mexico, Mexico City

    Astronomers searching the atmospheres of alien worlds for gases that might be produced by life can’t rely on the detection of just one type, such as oxygen, ozone, or methane, because in some cases these gases can be produced non-biologically, according to extensive simulations by researchers in the NASA Astrobiology Institute’s Virtual Planetary Laboratory.

    two
    Left: Ozone molecules in a planet’s atmosphere could indicate biological activity, but ozone, carbon dioxide and carbon monoxide — without methane, is likely a false positive. Right: Ozone, oxygen, carbon dioxide and methane — without carbon monoxide, indicate a possible true positive. Image Credit: NASA

    The researchers carefully simulated the atmospheric chemistry of alien worlds devoid of life thousands of times over a period of more than four years, varying the atmospheric compositions and star types.

    “When we ran these calculations, we found that in some cases, there was a significant amount of ozone that built up in the atmosphere, despite there not being any oxygen flowing into the atmosphere,” said Shawn Domagal-Goldman of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This has important implications for our future plans to look for life beyond Earth.”

    Methane is a carbon atom bound to four hydrogen atoms. On Earth, much of it is produced biologically (flatulent cows are a classic example), but it can also be made inorganically; for example, volcanoes at the bottom of the ocean can release the gas after it is produced by reactions of rocks with seawater.

    Ozone and oxygen were previously thought to be stronger biosignatures on their own. Ozone is three atoms of oxygen bound together. On Earth, it is produced when molecular oxygen (two oxygen atoms) and atomic oxygen (a single oxygen atom) combine, after the atomic oxygen is created by other reactions powered by sunlight or lightning. Life is the dominant source of the molecular oxygen on our planet, as the gas is produced by photosynthesis in plants and microscopic, single-cell organisms. Because life dominates the production of oxygen, and oxygen is needed for ozone, both gases were thought to be relatively strong biosignatures.

    But this study demonstrated that both molecular oxygen and ozone can be made without life when ultraviolet light breaks apart carbon dioxide (a carbon atom bound to two oxygen atoms). Their research suggests this non-biological process could create enough ozone for it to be detectable across space, so the detection of ozone by itself would not be a definitive sign of life.

    “However, our research strengthens the argument that methane and oxygen together, or methane and ozone together, are still strong signatures of life,” said Domagal-Goldman. “We tried really, really hard to make false-positive signals for life, and we did find some, but only for oxygen, ozone, or methane by themselves.”

    orb
    Credit: NASA Ames/SETI Institute/JPL-Caltech

    Domagal-Goldman and Antígona Segura from the Universidad Nacional Autónoma de México in Mexico City are lead authors of a paper about this research, along with astronomer Victoria Meadows, geologist Mark Claire, and Tyler Robison, an expert on what Earth would look like as an extrasolar planet. The paper appeared in the Astrophysical Journal Sept. 10, and is available online.

    Methane and oxygen molecules together are a reliable sign of biological activity because methane doesn’t last long in an atmosphere containing oxygen-bearing molecules. “It’s like college students and pizza,” says Domagal-Goldman. “If you see pizza in a room, and there are also college students in that room, chances are the pizza was freshly delivered, because the students will quickly eat the pizza. The same goes for methane and oxygen. If both are seen together in an atmosphere, the methane was freshly delivered because the oxygen will be part of a network of reactions that will consume the methane. You know the methane is being replenished. The best way to replenish methane in the presence of oxygen is with life. The opposite is true, as well. In order to keep the oxygen around in an atmosphere that has a lot of methane, you have to replenish the oxygen, and the best way to do that is with life.”

    Scientists have used computer models to simulate the atmospheric chemistry on planets beyond our solar system (exoplanets) before, and the team used a similar model in its research. However, the researchers also developed a program to automatically compute the calculations thousands of times, so they could see the results with a wider range of atmospheric compositions and star types.

    In doing these simulations, the team made sure they balanced the reactions that could put oxygen molecules in the atmosphere with the reactions that might remove them from the atmosphere. For example, oxygen can react with iron on the surface of a planet to make iron oxides; this is what gives most red rocks their color. A similar process has colored the dust on Mars, giving the Red Planet its distinctive hue. Calculating the appearance of a balanced atmosphere is important because this balance would allow the atmosphere to persist for geological time scales. Given that planetary lifetimes are measured in billions of years, it’s unlikely astronomers will happen by chance to be observing a planet during a temporary surge of oxygen or methane lasting just thousands or even millions of years.

    It was important to make the calculations for a wide variety of cases, because the non-biological production of oxygen is subject to both the atmospheric and stellar environment of the planet. If there are a lot of gases that consume oxygen, such as methane or hydrogen, then any oxygen or ozone produced will be destroyed in the atmosphere.

    However, if the amount of oxygen-consuming gases is vanishingly small, the oxygen and the ozone might stick around for a while. Likewise, the production and destruction of oxygen, ozone, and methane is driven by chemical reactions powered by light, making the type of star important to consider as well. Different types of stars produce the majority of their light at specific colors.

    For example, massive, hot stars or stars with frequent explosive activity produce more ultraviolet light. “If there is more ultraviolet light hitting the atmosphere, it will drive these photochemical reactions more efficiently,” said Domagal-Goldman. “More specifically, different colors (or wavelengths) of ultraviolet light can affect oxygen and ozone production and destruction in different ways.”

    Astronomers detect molecules in exoplanet atmospheres by measuring the colors of light from the star the exoplanet is orbiting. As this light passes through the exoplanet’s atmosphere, some of it is absorbed by atmospheric molecules. Different molecules absorb different colors of light, so astronomers use these absorption features as unique “signatures” of the type and quantity of molecules present.

    “One of the main challenges in identifying life signatures is to distinguish between the products of life and those compounds generated by geological processes or chemical reactions in the atmosphere. For that we need to understand not only how life may change a planet but how planets work and the characteristics of the stars that host such worlds”, said Segura.

    The team plans to use this research to make recommendations about the requirements for future space telescopes designed to search exoplanet atmospheres for signs of alien life.

    “Context is key – we can’t just look for oxygen, ozone, or methane alone,” says Domagal-Goldman. “To confirm life is making oxygen or ozone, you need to expand your wavelength range to include methane absorption features. Ideally, you’d also measure other gases like carbon dioxide and carbon monoxide [a molecule with one carbon atom and one oxygen atom]. So we’re thinking very carefully about the issues that could trip us up and give a false-positive signal, and the good news is by identifying them, we can create a good path to avoid the issues false positives could cause. We now know which measurements we need to make. The next step is figuring out what we need to build and how to build it.”

    See the full article here.

    NASA

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 7:18 am on September 11, 2014 Permalink | Reply
    Tags: , , , , , Exoplanets   

    From Astrobiology: “In the Zone. The Venus Zone: Seeking the Twin of our Twin Among the Stars” 

    Astrobiology Magazine

    Astrobiology Magazine

    Sep 10, 2014
    Sheyna E. Gifford

    What if, in our quest to find another Earth, we happen upon another Venus?

    We should celebrate, of course. Venus is often called Earth’s “twin” because it shares of lot of our home planet’s physical characteristics: surface area, composition and density. Also, roughly speaking, both planets inhabit the area around the Sun’s habitable zone – though Venus is near the inner edge, while we on Earth occupy the relative center. Bearing the similarities and differences in mind, scientists Ravi Kumar Kopparapu, Stephen Kane and Shawn Domagal-Goldman explored how distant analogs to Venus might be detected and differentiated from Earth-like planets occupying the same relative space. The paper pinpointing their finding was published in Astrophysical Journal Letters on 9/10/2014.

    Successfully detecting analogs of our inner planets out in the Universe, as Kopparapu and colleagues describe, means that at least two important events have taken place.

    One says something about us. At present, our ability to identify the existence of other planetary systems is increasing by the day. When it comes to divining which exoplanet is a mini-Neptune and which is a mega-Earth, we still have a ways to go. Gaining the ability to pick out Venus-like planets will imply that we have gotten really good at sorting exoplanets.

    The other is a larger statement about the Universe: If Venus-like planets are found in abundance, then Solar Systems like ours may be the rule rather than the exception. Discovering a twin to Venus around another star might well spark our interest in focusing our observations there, both for signs of another Earth and for clues about the dynamics of exoplanetary systems that harbor conditions similar to our own.

    In their paper, Kopparapu, Domagal-Goldman and Kane explain how we can determine the distance between a planet and a star from calculations we can make today. They project that in the near future, when the James Webb Space Telescope takes to the skies, measurements of exoplanetary atmospheres will distinguish Venus-like from Earth-like from Mars-like. In the meantime, Kane and colleagues made some important calculations that will assist astronomers in the search for distant Venuses.

    NASA Webb Telescope
    NASA/Webb

    vennus
    Not every planet in or near a habitable zone is habitable. Inhospitable Venus is an excellent example. Credit: NASA/JPL/Caltech

    First, they estimated how close a planet can be to a star and still retain its atmosphere. Those figures pertain to planets like Mercury, with close-in orbits where the Solar Wind strips away nearly all atmospheric particles. Then, they approximated the furthest distance from a star likely to sustain a planet-wide runaway greenhouse effect. Taken together, these parameters describe the Venus zone: a place where we can start looking for planets with characteristics of own second planet from the Sun.

    Before we move on to finding planets in other solar systems, we should talk a bit about our own Solar System. Here to do that and then discuss his findings is Dr. Shawn Domagal-Goldman, one of the paper’s authors and the mind behind The Pale Blue Blog at astrobio.net.

    Astrobiology Magazine (AM): Shawn, the discovery of just how much Earth and Venus differ is relatively recent. What did it take for us to figure out that our own twin in the Solar System was not just uninhabited, but utterly uninhabitable?

    Domagal-Goldman: This is one of the things we’ve learned through telescope and spacecraft observations of Venus over the last century or so. And this highlights two of the things I love about this paper – it leverages what we’ve learned about planets from observations of the ones in our own solar system to inform exoplanet data; and it also reinforces the notion that two planets with fairly Earth-like “astrophysical” properties such as mass/radius can be dramatically different in terms of their habitability.

    AM: Where is our own “Venus zone”?

    Domagal-Goldman: The outer edge of the “Venus zone” is, by the way we’ve defined it here, the same as the inner edge of the habitable zone. This is roughly the “border” between where we think a planet is more likely to be Venus (closer to the Sun than the border) or more like Earth (further from the Sun than the border). This border therefore is between Earth and Venus. The inner edge of the “Venus zone” is the distance at which Venus would lose it’s atmosphere from all high energy input from the Sun. In our system, this is VERY close to the Sun – about twice as close to the Sun as Mercury is.

    AM: We’re just beginning to find rocky planets in so-called habitable zones around other stars. Why is now a good time to start breaking up these habitable zones into discrete bands that reflect Earth and Venus? How will we be able to tell a Venus-zone from an Earth-zone at such tremendous distances? Will there be a Mars-zone as well, when all is said and done?

    image
    In the present-day Solar System with the Sun in its current state, Venus is outside of the habitable zone (HZ) – or rather, it is closer to the Sun than the inner boundary of where water will be found in liquid form. The stability of water as a liquid sets the lines for the traditional habitable zone, outlined here in blue. However, for exoplantary systems with characteristics distinct from ours – where the stars exhibit different luminosity, the planets rotate differently, or the atmosphere conditions vary on those planets vary – the HZ will vary in size and distance from the star. Image Credit: NASA

    Domagal-Goldman:: There could be a Mars-zone, as well! But getting at that will require us to understand the degree to which Mars was habitable, for how long, and what caused the demise of the red planet’s habitability. These are all questions currently being explored by Curiosity, and we look forward to answers on all those topics.

    NASA Mars Curiosity
    NASA/Mars Curiosity

    Ultimately, these sorts of categorizations are going to be done better when we can analyze exoplanets in more detail with bigger future telescopes. The reason we’re doing all this now is for two reasons. First, this gives the community scientific hypotheses for us to test with that sort of mission. Second, it helps us design those missions, and prioritize which objects we would look at first when those missions happen.

    AM: The size and location of the Venus zone in each system is going to be dependent on a lot of factors: for example, the luminosity and size of the primary star. A white dwarf star will have a Venus zone much smaller and closer in than our Sun’s. What else will we need to consider in trying to size up Venus zones?

    Domagal-Goldman: The other thing that’s really needed now is more simulations of Venus-like atmospheres. This is something that’s very difficult to do, as Venus has been one of the planets that is most difficult to simulate in our computer models. Making advances in that will help us determine the boundaries of both the Venus zone and the habitable zone. Ultimately, we want to define these boundaries with observations from telescopes, but until that happens the best thing we can do will be to improve our simulations and use those results to refine the concept of the Venus zone.

    AM: The Kepler Space Telescope has been the workhorse of our planet-hunting mission thus far. When the James Webb takes to the skies, what will change, in terms of finding the Venus Zones, the Venus-analogs, the Earth-analogs and places where we should focus the search for life?

    NASA Kepler Telescope
    NASA/Kepler

    Domagal-Goldman: If we’re lucky, we’ll get a couple Venus-like candidates to study, as the first tests of the hypotheses in this paper. And if we’re extremely lucky, we may get a potentially habitable world or two for us to study, as well. That will be the first mission to move us from studying the “physics” of these planets to being able to study the “chemistry” for a large number of them. Eventually, with a future mission, the goal is to study the biology of such worlds.

    See the full article here.

    NASA

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 7:19 am on September 10, 2014 Permalink | Reply
    Tags: , , , , Exoplanets,   

    From SPACE.com: “What Is the Fermi Paradox?” 

    space-dot-com logo

    SPACE.com

    April 02, 2014
    Elizabeth Howell

    The Fermi Paradox seeks to answer the question of where the aliens are. Given that our star and Earth are part of a young planetary system compared to the rest of the universe — and that interstellar travel might be fairly easy to achieve — the theory says that Earth should have been visited by aliens already.

    As the story goes, Enrico Fermi (an Italian physicist) first came out with the theory with a casual lunchtime remark in 1950. The implications, however, have had extraterrestrial researchers scratching their heads in the decades since.

    “Fermi realized that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire galaxy,” the Search For Extraterrestrial Intelligence (SETI) said on its website.

    “Within ten million years, every star system could be brought under the wing of empire. Ten million years may sound long, but in fact it’s quite short compared with the age of the galaxy, which is roughly ten thousand million years. Colonization of the Milky Way should be a quick exercise.”

    Plentiful planets

    It is true that the universe is incredibly vast and old. One estimate says the universe spans 92 billion light-years in diameter (while growing faster and faster). Separate measurements indicate it is about 13.82 billion light-years old. At first blush, this would give alien civilizations plenty of time to propagate, but then they would have a cosmic distance barrier to cross before getting too far into space.

    The sheer number of planets that we have found outside of our solar system, however, indicates that life could be plentiful. A November 2013 study using data from the Kepler Space Telescope suggested that one in five sun-like stars has an Earth-size planet orbiting in the habitable region of its star, the zone where liquid water would be possible. That zone is not necessarily an indication of life, as other factors, such as the planet’s atmosphere, come into play. Further, “life” could encompass anything from bacteria to starship-sailing extraterrestrials.

    NASA Kepler Telescope
    NASA/Kepler

    A few months later, Kepler scientists released a “planet bonanza” of 715 newly discovered worlds, pioneering a new technique called “verification by multiplicity.” The theory essentially postulates that a star that appears to have multiple objects crossing its face or tugging at it would have planets, as opposed to stars. (A multiple star system at such close proximity would destabilize over time, the technique postulates.) Using this will accelerate the pace of exoplanet discovery, NASA said in 2014.

    exo

    Our understanding of astrobiology (life in the universe) is just at a beginning, however. One challenge is these exoplanets are so far away that it is next to impossible for us to send a probe out to look at them. Another obstacle is even within our own solar system, we haven’t eliminated all the possible locations for life. We know from looking at Earth that microbes can survive in extreme temperatures and environments, giving rise to theories that we could find microbe-like life on Mars, the icy Jovian moon Europa, or perhaps Saturn’s Enceladus or Titan.

    All of this together means that even within our own Milky Way Galaxy — the equivalent of the cosmic neighborhood — there should be many Earth-size planets in habitable zones that could host life. But what are the odds of these worlds having starfarers in their bounds?

    Life: plentiful, or rare?

    The odds of intelligent life are estimated in the Drake Equation, which seeks to figure out the number of civilizations in the Milky Way that seek to communicate with each other. In the words of SETI, the equation (written as N = R* • fp • ne • fl • fi • fc • L) has the following variables:

    N = The number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable.

    R* = The rate of formation of stars suitable for the development of intelligent life.

    fp = The fraction of those stars with planetary systems.

    ne = The number of planets, per solar system, with an environment suitable for life.

    fl = The fraction of suitable planets on which life actually appears.

    fi = The fraction of life bearing planets on which intelligent life emerges.

    fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.

    L = The length of time such civilizations release detectable signals into space.

    None of these values are known with any certainty right now, which makes predictions difficult for astrobiologists and extraterrestrial communicators alike.

    There is another possibility that would dampen the search for radio signals or alien spacecraft, however: that there is no life in the universe besides our own. While SETI’s Frank Drake and others suggested there could be 10,000 civilizations seeking communications in the galaxy, a 2011 study later published in the Proceedings of the National Academy of Sciences suggested that Earth could be a rare bird among planets.

    It took at least 3.5 billion years for intelligent life to evolve, the theory by Princeton University researchers David Spiegel and Edwin Turner said, which indicates it takes a lot of time and luck for this to happen.

    Other explanations for the Fermi paradox include extraterrestrials “spying” on Earth, ignoring it altogether, visiting it before civilization arose, or visiting it in a way that we can’t detect.

    See the full article here.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 7:47 am on August 29, 2014 Permalink | Reply
    Tags: , , , , Exoplanets,   

    From SETI Institute: “How Can We Find Tiny Particles In Exoplanet Atmospheres?” 


    SETI Institute

    August 28 2014

    Adrian Brown
    SETI Institute
    E-mail: abrown@seti.org
    Tel: +1 650 960-4223

    Seth Shostak, Media Contact
    SETI Institute
    E-mail: seth@seti.org
    Tel: +1 650 960-4530

    It may seem like magic, but astronomers have worked out a scheme that will allow them to detect and measure particles ten times smaller than the width of a human hair, even at many light-years distance. They can do this by observing a blue tint in the light from far-off objects caused by the way in which small particles, no more than a micron in size (one-thousandth of a millimeter) scatter light.

    disc
    Credit: NASA/JPL

    In a recent study conducted by Adrian Brown of the SETI Institute, the broad outlines of this process have been worked out. “The effect is related to a familiar phenomenon known as Rayleigh scattering,” says Brown. “And that’s something everyone has seen: it makes the sky blue.”

    By analyzing spectroscopic data from the Cassini orbiter, the Mars Reconnaissance Orbiter, and ground-based telescopes, Brown has managed to document this blue enhancement in many nearby objects, including the rings of Saturn, its moons Dione and Epimetheus, Mars, the moon, and the tail of Comet 17P/Holmes.

    NASA Cassini Spacecraft
    NASA/Cassini

    mars
    NASA/ Mars Reconnaissance Orbiter

    Brown’s theoretical study of the phenomenon showed that the spectral bluing occurs any time sufficiently small objects are in our field of view. In his studies, he considered particles between 0.1 and 1.0 microns in size. A human hair is roughly 17 microns in diameter.

    So why isn’t the ground beneath our feet blue? Brown’s research suggests that the effect is quickly damped by other objects that, despite being of the same type, have different size distributions. The effect depends on having many particles within a narrow range of size. In addition, too many tiny particles might turn objects white. As an example of the latter, a glass of milk appears white because of multiple scattering from fat globules, and clouds appear white due to multiple scattering from water aerosols (droplets).

    Consequently, the bluing effect requires some process that forms lots of particles of almost identical size. Simply establishing that such a process is present can give researchers clues to the history and conditions on extraterrestrial bodies.

    “This technique would, in principle, allow us to find extremely tiny particles in the atmospheres or on the surfaces of exoplanets that are tens or thousands of light-years away,” Brown says.

    The research was published in the September 1 issue of Icarus.

    See the full article here.

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
    Privacy PolicyQuestions and Comments

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 8:24 am on August 22, 2014 Permalink | Reply
    Tags: , , , , Exoplanets,   

    From SPACE.com: “How to Search for E.T. by Scanning Alien Skies” 

    space-dot-com logo

    SPACE.com

    August 04, 2014
    Charles Q. Choi

    In the future, astronomers could detect hints of alien life by scanning the atmospheres of distant worlds with advanced space telescopes, researchers say.

    In the past two decades, astronomers have confirmed the existence of more than 1,700 worlds outside Earth’s solar system. Many of these alien planets lie in the habitable zones of stars, areas potentially warm enough for worlds to harbor liquid water of their surfaces. This has inspired hope that one day scientists might detect life as it is known on Earth on such exoplanets, since there is life pretty much everywhere water exists on Earth.

    exo
    The alien planet Kepler-186f is the first extrasolar world ever found to be about the size of Earth and in the habitable zone of its parent star. But if scientists ever hope to try to find life on such a planet, giant new space telescopes are needed, researchers say.
    Credit: NASA Ames/SETI Institute/JPL-Caltech

    “Astronomers have now ascertained, statistically speaking, that every star in our Milky Way galaxy should have at least one planet and that small rocky planets are extremely common,” planetary scientist Sara Seager of the Massachusetts Institute of Technology wrote in an analysis appearing online Monday (Aug. 4) in the journal Proceedings of the National Academy of Sciences.

    “Our own galaxy has 100 billion stars, and our universe has upwards of 100 billion galaxies, making the chance for life elsewhere seem inevitable based on sheer probability,” she added.

    One strategy to hunt for signs of such extraterrestrial life involves looking for ways that organisms might alter a world’s appearance. For example, key chemicals might change the spectrum of light seen from the atmospheres of those planets. These searches focus on biosignature gases — chemicals or combinations of chemicals that life could produce, but that processes other than life could not or would be unlikely to create.

    “In the coming decade or two, we will have a lucky handful of potentially habitable exoplanets with atmospheres that can be observed in detail with the next generation of sophisticated space telescopes,” Seager wrote.

    So far, astronomers have studied more than three dozen exoplanet atmospheres. These observations have yielded enough data for researchers to glimpse both the future prospects and limitations of the atmosphere-based method of searching for alien life. One challenge is that exoplanet atmospheres continue to surprise researchers. For instance, scientists have detected hazes and clouds on planets once thought too hot for such features to form.

    “The atmospheres of a few of the exoplanets we have looked at do not appear as expected,” Seager told Space.com. This suggests that researchers should try their best to expect the unexpected when building scientific instruments designed to analyze exoplanetary atmospheric compositions.

    In the near future, the James Webb Space Telescope (JWST), planned for launch in 2018, can study the atmospheres of dozens of super-Earths, exoplanets slightly larger than Earth. The observatory may even be able to scan a number of worlds that might be habitable.

    NASA Webb Telescope
    NASA/Webb

    However, JWST will rely upon planetary “transits” to do such work, only scanning the atmospheres of planets that pass in front of their stars from the observatory’s perspective and are thus backlit by starlight. Ideally, researchers would like to scan exoplanet atmospheres by directly taking photos of the planets without having to wait for transits.

    The problem with such direct imaging of exoplanets is that any nearby Earthlike exoplanets or “Earth twins” would be about as faint as the faintest galaxies ever observed by the Hubble Space Telescope. However, these exoplanets are next to parent stars that are up to 10 billion times brighter than the planets themselves.

    NASA Hubble Telescope
    NASA/ESA Hubble

    “The challenge of direct imaging of an Earth analog is similar to the search for a firefly in the glare of a searchlight when the firefly and searchlight are 2,500 miles distant, the separation from the East Coast to the West Coast of the United States,” Seager wrote.

    To directly image Earth twins, researchers are currently pursuing two different strategies. One involves so-called internal coronographs, or systems within telescopes that can block out the light of stars to reveal the presence of any orbiting exoplanets. This requires mirrors that can focus starlight without scattering it; these reflectors must be smoothed to levels of less than a nanometer, or a billionth of a meter. (In comparison, the average human hair is about 100,000 nanometers wide.) Laboratory experiments have already demonstrated such a level of control, Seager noted.

    Another strategy to directly image Earth twins involves a starshade, a different system designed to hide the light of stars to reveal the presence of any orbiting exoplanets. However, a starshade does not fit inside a telescope; rather, it is a giant, sunflowerlike spacecraft. Most designs involve a starshade dozens of feet wide flying tens of thousands of miles in front of a telescope, carefully positioned to blot out the light of just one star at a time. Current lab experiments have created scaled-down versions of such devices that need to cast shadows about 10 times darker before they can find use in starshades.

    In the future, researchers could build very large space telescopes with apertures more than 33 feet (10 meters) wide capable of finding more than 100 potentially habitable exoplanets. The telescopes could then analyze those planets’ atmospheres for biosignature gases.

    “While we are closer than ever, it will still be a while before we have the capability to study small exoplanet atmospheres for biosignature gases,” Seager told Space.com.

    See the full article here.

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 5:02 pm on August 18, 2014 Permalink | Reply
    Tags: , , , , Exoplanets,   

    From NASA Science: “Exoplanet Measured with Remarkable Precision “ 

    NASA Science Science News

    August 18, 2014
    Dr. Tony Phillips

    Barely 30 years ago, the only planets astronomers had found were located right here in our own solar system. The Milky Way is chock-full of stars, millions of them similar to our own sun. Yet the tally of known worlds in other star systems was exactly zero.

    What a difference a few decades can make.

    As 2014 unfolds, astronomers have not only found more than a thousand “exoplanets” circling distant suns, but also they’re beginning to make precise measurements of them. The old void of ignorance about exoplanets is now being filled with data precise to the second decimal place.

    A team led by Sarah Ballard, a NASA Carl Sagan Fellow at the University of Washington in Seattle, recently measured the diameter of a “super Earth” to within an accuracy of 148 miles total or about 1 percent — remarkable accuracy for an exoplanet located about 300 light years from Earth.

    “It does indeed seem amazing,” says Ballard. “The landscape of exoplanet research has changed to an almost unrecognizable degree since I started graduate school in 2007.”
    Auroras Underfoot (signup)

    To size up the planet, named “Kepler 93 b,” Ballard used data from NASA’s Kepler and Spitzer Space Telescopes.

    NASA Kepler Telescope
    NASA/Kepler

    NASA Spitzer Telescope
    NASA/Spitzer

    First, Kepler discovered the planet. As seen from Earth, Kepler 93 b passes directly in front of its parent star, causing the starlight to dim during the transit. That dimming, which occurs once per orbit, is what allowed Kepler mission scientists to find the planet in the first place.

    Next, both Spitzer and Kepler recorded multiple transits at visible and infrared wavelengths. Data from the observatories agreed: Kepler 93 b was really a planet and not some artifact of stellar variability. Ballard then knew that by looking carefully at the light curve she could calculate the size of the planet relative to the star.

    At that point, the only missing piece was the diameter of the star itself.

    “The precision with which we measured the size of the planet is linked directly to our measurement of the star,” says Ballard. “And we measured the star using a technique called asteroseismology.”

    Most people have heard of “seismology,” the study of seismic waves moving through the Earth. “We can learn a lot about the structure of our planet by studying seismic waves,” she says.

    Asteroseismology is the same thing, except for stars: The outer layers of stars boil like water on top of a hot stove. Those convective motions create seismic waves that bounce around inside the core, causing the star to ring like an enormous bell. Kepler can detect that “ringing,” which reveals itself as fluctuations in a star’s brightness.

    Ballard’s colleague, University of Birmingham professor Bill Chaplin led the asteroseismic analysis for Kepler-93 b. “By analyzing the seismic modes of the star, he was able to deduce its radius and mass to an accuracy of a percent,” she says.

    The new measurements confirm that Kepler-93 b is a “super-Earth” sized exoplanet, with a diameter about one-and-a-half times the size of our planet. Previous measurements by the Keck Observatory in Hawaii had put Kepler-93 b’s mass at about 3.8 times that of Earth. The density of Kepler-93 b, derived from its mass and newly obtained radius, suggests the planet is very likely made of iron and rock, like Earth itself.

    Keck Observatory
    Keck Observatory Interior
    Keck

    Although super-Earths are common in the galaxy, none exist in our solar system. That makes them tricky to study. Ballard’s team has shown, however, that it is possible to learn a lot about an exoplanet even when it is very far away.

    See the full article here.

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

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

    NASA

    ScienceSprings relies on technology from

    MAINGEAR computers

    Lenovo
    Lenovo

    Dell
    Dell

     
  • richardmitnick 8:55 am on July 24, 2014 Permalink | Reply
    Tags: , , , , Exoplanets, ,   

    From NASA/JPL at Caltech: “The Most Precise Measurement of an Alien World’s Size” 

    NASA/JPL

    Thanks to NASA’s Kepler and Spitzer Space Telescopes, scientists have made the most precise measurement ever of the radius of a planet outside our solar system. The size of the exoplanet, dubbed Kepler-93b, is now known to an uncertainty of just 74 miles (119 kilometers) on either side of the planetary body.

    art
    Using data from NASA’s Kepler and Spitzer Space Telescopes, scientists have made the most precise measurement ever of the size of a world outside our solar system, as illustrated in this artist’s conception.

    NASA Kepler Telescope
    NASA/Kepler

    NASA Spitzer Telescope
    NASA/Spitzer

    The findings confirm Kepler-93b as a “super-Earth” that is about one-and-a-half times the size of our planet. Although super-Earths are common in the galaxy, none exist in our solar system. Exoplanets like Kepler-93b are therefore our only laboratories to study this major class of planet.

    With good limits on the sizes and masses of super-Earths, scientists can finally start to theorize about what makes up these weird worlds. Previous measurements, by the Keck Observatory in Hawaii, had put Kepler-93b’s mass at about 3.8 times that of Earth. The density of Kepler-93b, derived from its mass and newly obtained radius, indicates the planet is in fact very likely made of iron and rock, like Earth.

    “With Kepler and Spitzer, we’ve captured the most precise measurement to date of an alien planet’s size, which is critical for understanding these far-off worlds,” said Sarah Ballard, a NASA Carl Sagan Fellow at the University of Washington in Seattle and lead author of a paper on the findings published in the Astrophysical Journal.

    “The measurement is so precise that it’s literally like being able to measure the height of a six-foot tall person to within three quarters of an inch — if that person were standing on Jupiter,” said Ballard.

    Kepler-93b orbits a star located about 300 light-years away, with approximately 90 percent of the sun’s mass and radius. The exoplanet’s orbital distance — only about one-sixth that of Mercury’s from the sun — implies a scorching surface temperature around 1,400 degrees Fahrenheit (760 degrees Celsius). Despite its newfound similarities in composition to Earth, Kepler-93b is far too hot for life.

    To make the key measurement about this toasty exoplanet’s radius, the Kepler and Spitzer telescopes each watched Kepler-93b cross, or transit, the face of its star, eclipsing a tiny portion of starlight. Kepler’s unflinching gaze also simultaneously tracked the dimming of the star caused by seismic waves moving within its interior. These readings encode precise information about the star’s interior. The team leveraged them to narrowly gauge the star’s radius, which is crucial for measuring the planetary radius.

    Spitzer, meanwhile, confirmed that the exoplanet’s transit looked the same in infrared light as in Kepler’s visible-light observations. These corroborating data from Spitzer — some of which were gathered in a new, precision observing mode — ruled out the possibility that Kepler’s detection of the exoplanet was bogus, or a so-called false positive.

    Taken together, the data boast an error bar of just one percent of the radius of Kepler-93b. The measurements mean that the planet, estimated at about 11,700 miles (18,800 kilometers) in diameter, could be bigger or smaller by about 150 miles (240 kilometers), the approximate distance between Washington, D.C., and Philadelphia.

    Spitzer racked up a total of seven transits of Kepler-93b between 2010 and 2011. Three of the transits were snapped using a “peak-up” observational technique. In 2011, Spitzer engineers repurposed the spacecraft’s peak-up camera, originally used to point the telescope precisely, to control where light lands on individual pixels within Spitzer’s infrared camera.

    The upshot of this rejiggering: Ballard and her colleagues were able to cut in half the range of uncertainty of the Spitzer measurements of the exoplanet radius, improving the agreement between the Spitzer and Kepler measurements.

    “Ballard and her team have made a major scientific advance while demonstrating the power of Spitzer’s new approach to exoplanet observations,” said Michael Werner, project scientist for the Spitzer Space Telescope at NASA’s Jet Propulsion Laboratory, Pasadena, California.

    JPL manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

    NASA’s Ames Research Center in Moffett Field, California, is responsible for Kepler’s ground system development, mission operations and science data analysis. JPL managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA’s 10th Discovery Mission and was funded by the agency’s Science Mission Directorate.

    See the full article here.

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

    Caltech Logo
    jpl


    ScienceSprings is powered by MAINGEAR computers

     
  • richardmitnick 6:36 pm on July 23, 2014 Permalink | Reply
    Tags: , , , , Exoplanets, ,   

    From SPACE.com: “Newfound Alien Planet Has Longest Year Known for Transiting World” 

    space-dot-com logo

    SPACE.com

    July 22, 2014
    Mike Wall, Senior Writer

    A newfound alien planet is one for the record books.

    The alien planet Kepler-421b — which crosses the face of, or transits, its host star from Earth’s perspective — takes 704 Earth days to complete one orbit, and thus has the longest year known for any transiting alien world, researchers said. (For comparison, Earth orbits the sun once every 365 days, and Mars completes a lap every 780 days.)

    “Finding Kepler-421b was a stroke of luck,” study lead author David Kipping, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, said in a statement. “The farther a planet is from its star, the less likely it is to transit the star from Earth’s point of view. It has to line up just right.”

    To be clear, Kepler-421b does not have the longest year of any known alien planet. Many nontransiting worlds have much more far-flung orbits, including the gas giant GU Piscium b, which takes about 160,000 years to complete a lap around its host star.

    gu
    The planet GU Psc b and its star GU Psc composed of visible and infrared images from the Gemini South telescope and an infrared image from the CFHT. Because infrared light is invisible to the naked eye, astronomers use a colour code in which infrared light is represented by the colour red. GU Psc b is brighter in infrared than in other filters, which is why it appears red in this image.

    Gemini South telescope
    Gemini South

    Canada-France-Hawaii Telescope
    Canada-France-Hawaii Telescope

    Kepler-421b, which is about the size of Uranus, is located about 1,000 light-years from Earth, in the constellation Lyra. It was spotted by NASA’s Kepler space telescope, which launched in March 2009 to hunt for transiting exoplanets by noting the tiny brightness dips caused when they cross in front of their stars.

    Lyra

    NASA Kepler Telescope
    NASA/Kepler

    Kepler has found nearly 1,000 alien worlds to date and has flagged more than 3,000 other “candidates” that still need to be confirmed by follow-up observations or study. Mission team members expect that at least 90 percent of these candidates will eventually turn out to be bona fide planets.

    The spacecraft suffered a glitch in May 2013 that ended its original mission, but NASA recently signed off on a new mission, called K2, that will keep Kepler hunting for exoplanets, in addition to other cosmic bodies and phenomena.

    Most of Kepler’s finds thus far are worlds that orbit relatively close to their parent stars, since such planets transit relatively frequently. The instrument has generally required three transits to conclusively identify an exoplanet, but Kepler-421b was detected after it crossed its host star’s face just twice, researchers said.

    Kepler-421b circles its parent star, which is cooler and dimmer than Earth’s sun, at an average distance of 100 million miles (160 million kilometers), researchers said. This places the exoplanet beyond its solar system’s “snow line” — the boundary between rocky and gaseous planets. (Beyond the snow line, ice grains glom together to form gas giants, such as Jupiter and Saturn.)

    Gaseous planets often don’t remain beyond the snow line, however. Astronomers have discovered many “hot Jupiters” — giant worlds that have migrated inward significantly over time and now complete an orbit in just a few days (or, in some cases, a matter of hours).

    In fact, Kepler-421b’s lack of movement makes it remarkable, Kipping said.

    “This is the first example of a potentially nonmigrating gas giant in a transiting system that we’ve found,” he said.

    The new study has been accepted for publication in The Astrophysical Journal.

    See the full article here.


    ScienceSprings is powered by MAINGEAR computers

     
  • richardmitnick 8:22 am on July 17, 2014 Permalink | Reply
    Tags: , , , , Exoplanets,   

    From SPACE.com: “The Hunt for Exoplanets Heats Up” 

    SpacedotcomHeader

    July 16, 2014
    Kelen Tuttle, The Kavli Foundation

    It’s a time of amazing discovery in the hunt for planets in other solar systems. Over the past six months, more than 700 exoplanets have been found. It seems that each week brings the announcement of another foreign world: a rocky orb that seems much like Earth except that it’s 17 times more massive; a colossal planet that orbits its star at a whopping 2,000 times the distance between Earth and our sun; an Earth-like planet in a two-sun system.

    On July 9, three astrophysicists — Zachory Berta-Thompson, Bruce Macintosh and Marie-Eve Naud — came together to discuss this explosion in exoplanet discovery in a live webcast hosted by The Kavli Foundation, part of a continuing series that gives viewers a chance to ask questions of scientists at the forefront of some of the world’s most exciting research. (To keep up to date on future webcasts, follow the foundation on Twitter: @KavliFoundation)

    emv
    Marie-Eve Naud is the University of Montreal Ph.D. student who led analysis that recently uncovered a previously unknown giant planet using infrared light. The planet, known as GU Pisces b, is one of the most unusual exoplanets found to-date, with a mass 10 times greater than Jupiter’s and orbiting its star at 2,000 times the distance between Earth and our sun.

    “What is really fascinating at this stage of exoplanet science is that we have many methods, and all the methods can help to find given planets — planets with certain characteristics — and bring different information,” said Naud, a University of Montreal Ph.D. student who led a recent study that discovered a strange gas giant exoplanet called GU Pisces b. “When we are able to combine different methods, we are able to see so much more.”

    Combining planet-hunting methods has not only enabled the recent explosion in exoplanet discovery , but has also increased what can be inferred about each planet. Scientists are now able to determine an exoplanet’s characteristics including its size, mass and density, as well as the chemical make-up of the planet and its atmosphere.

    zbt
    Zachory Berta-Thompson is the Torres Fellow for Exoplanetary Research at the MIT Kavli Institute for Astrophysics and Space Research. He hunts for exoplanets as a member of the MEarth Project, a survey to find small planets orbiting the closest, smallest stars.

    What’s especially exciting about identifying these chemicals is that they “can tell you things like the history of the planet — how it formed,” said Macintosh, a member of the Kavli Institute for Particle Astrophysics and Cosmology and the principal investigator for the Gemini Planet Imager. “We think we understand enough about the process that formed planets in our solar system to see that it left a chemical signature in the atmosphere of, say, Jupiter and we can try to look for that same chemical signature in the atmosphere of other planets.”

    bt
    Bruce Macintosh is the principal investigator for the Gemini Planet Imager, which searches for planets from the Gemini South telescope. GPI recently snapped its first image, thereby producing the best-ever direct photo of a planet outside our solar system. Macintosh is also a Professor of Physics at Stanford University and a member of the Kavli Institute for Particle Astrophysics and Cosmology.

    NOAO Gemini Planet Imager
    Gemini Planet Imager

    Gemini South telescope
    Gemini South

    All three scientists agreed that, in addition to finding and characterizing planets, there’s another burning question that makes them excited to come to work each day: the hunt for planets that could support life.

    “I think it’ll be really tough, but … thanks to the Kepler mission , we now know that the rate of occurrence of potentially habitable planets around small stars is … more than one out of ten,” said Berta-Thompson, the Torres Fellow for Exoplanetary Research at the MIT Kavli Institute for Astrophysics and Space Research. “And so this does really increase our chances.”

    For more on the three astrophysicists’ expectations for finding life on other planets, their favorite of the 1700 planets discovered so far, and the burning questions that makes it exciting from them to come to work each morning, watch the complete discussion, recorded live during a Google Hangout.

    See the full article here.


    ScienceSprings is powered by MAINGEAR computers

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
Follow

Get every new post delivered to your Inbox.

Join 322 other followers

%d bloggers like this: