NASA launches telescope to seek Earth-like planets

Discussion in 'International Politics' started by LETHALFORCE, Mar 7, 2009.

  1. LETHALFORCE

    LETHALFORCE Moderator Moderator

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    http://www.spacedaily.com/reports/NASA_launches_telescope_to_seek_Earth-like_planets_999.html

    NASA launches telescope to seek Earth-like planets

    by Staff Writers
    Washington (AFP) March 6, 2009
    The United States late Friday launched a space telescope whose three-year mission is to find Earth-like planets in the Milky Way galaxy.

    The Kepler telescope blasted off from Cape Canaveral Air Force Station, Florida, atop a Delta II rocket 10:49 pm (0349 GMT Saturday), according to the US space agency NASA.

    "This mission attempts to answer a question that is as old as time itself -- are other planets like ours out there?" said Ed Weiler, associate administrator for NASA's Science Mission Directorate.

    "It's not just a science mission, it's an historical mission."

    Kepler will stare at the same spot in space for three and a half years, taking in about 100,000 stars around the Cygnus and Lyra constellations of the Milky Way.

    At a cost of nearly 600 million dollars, it will be the National Aeronautics and Space Administration's first mission in search of Earth-like planets orbiting suns similar to ours, at just the right distance and temperature for life-sustaining water to exist.

    The telescope will be hunting for relatively small planets that are neither too hot nor too cold, are rocky and have liquid water -- essential life-sustaining conditions -- explained William Borucki, Kepler's principal investigator based at NASA's Ames Research Center in California.

    "If we find that many, it certainly will mean that life may well be common throughout our galaxy, that there is an opportunity for life to have a place to evolve," Borucki said.

    Equipped with the largest camera ever launched into space -- a 95-megapixel array of charge-coupled devices (CCDs) -- the Kepler telescope is able to detect the faint, periodic dimming of stars that planets cause as they pass by.

    "If Kepler were to look down at a small town on Earth at night from space, it would be able to detect the dimming of a porch light as somebody passed in front," according to Kepler project manager James Fanson.

    This is no small feat.

    "Trying to detect Jupiter-size planets crossing in front of their stars is like trying to measure the effect of a mosquito flying by a car's headlight," Fanson said.

    "Finding Earth-sized planets is like trying to detect a very tiny flea in that same headlight."

    Kepler's discoveries "may fundamentally alter humanity's view of itself," Jon Morse, astrophysics division director at the NASA's Washington headquarters, told a press conference last month.

    "The planetary census Kepler takes will be very important for understanding the frequency of Earth-size planets in our galaxy and planning future missions that directly detect and characterize such worlds around nearby stars."

    Ever since astronomers first turned their telescopes to the sky, humans have been searching for other planets. But the small size of planets compared to stars has complicated the task. Only eight planets have been found in our solar system -- Pluto is now considered a mere planetoid.

    Since 1995, some 337 planets have been found orbiting around stars outside our solar system, but they are all bigger than Earth and do not have Earth-like conditions that make life possible.

    The French-led COROT satellite, which has been in orbit since 2006, has already discovered the smallest extraterrestrial planet so far. At a little over twice the Earth's diameter, the planet is very close to its star and very hot, astronomers reported earlier this month.

    Astronomer Debra Fischer at San Francisco State University said that NASA's mission is a cornerstone in understanding what types of planets are formed around other stars.

    Information that Kepler will help compile, she said, "will help us chart a course toward one day imaging a pale blue dot like our planet, orbiting another star in our galaxy."
     
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  3. LETHALFORCE

    LETHALFORCE Moderator Moderator

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    From earths to moons -- search for life elsewhere expands



    From earths to moons -- search for life elsewhere expands

    by Staff Writers
    Paris (AFP) Sept 3, 2009
    A powerful orbital telescope launched in March with a mission to look for habitable counterparts to Earth should also be able to detect small moons that could nurture life, scientists said Thursday.
    The NASA spacecraft Kepler is designed to monitor more than 100,000 stars over the next three years, looking for telltale dips in their brightness as orbiting planets pass in front of them.

    These so-called transit events can yield tantalising details about exoplanets, as planets beyond our Solar System are known.

    So far, 358 exoplanets have been spotted since the first was found in 1995.

    Frustratingly, none is comparable to Earth.

    Our planet sits in the "Goldilocks zone" where the temperature is not too hot for our atmosphere to be stripped away nor too cold for our seas to freeze -- but just right to have liquid water, the stuff of life.

    Most of the finds have been gas giants, similar to Jupiter, rather than solid ones like Earth, and they orbit their stars at scorchingly close distances.

    Kepler, according to the new study, should have the power to find even Earth-like satellites of exoplanets.

    A team led by David Kipping of University College London modelled the properties of the instruments aboard Kepler and compared this with the expected signal strength that a habitable "exomoon" would generate.

    They found that habitable exomoons down to just a fifth of the mass of Earth could be spotted.

    No exomoon has been found yet, but this could change with the advances provided by Kepler, they believe.

    "For the first time, we have demonstrated that potentially habitable moons up to hundreds of light years away may be detected with current instrumentation," said Kipping.

    "It seems probable that many thousands, possibly millions, of habitable exomoons exist in the Galaxy and now we can start to look for them."

    Even if an Earth-like exoplanet or exomoon is found, we have no chance of getting there with our puny chemical-powered spaceships.

    Discovering such a place, though, would add a big piece to the puzzle as to whether life has the potential to exist elsewhere in the Universe.

    The paper appears in the journal Monthly Notices, published by Britain's Royal Astronomical Society.
     
  4. LETHALFORCE

    LETHALFORCE Moderator Moderator

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    Kepler telescope could find habitable moons - Space.com- msnbc.com

    Kepler telescope could find habitable moons
    Instrument is 1st aimed at detecting alien worlds closer to the size of Earth

    NASA's planet-hunting Kepler telescope, which astronomers hope will find Earth-like planets orbiting other stars, might also find habitable moons in other solar systems, new research suggests.

    Kepler's primary mission is to monitor thousands of stars looking for characteristic dips in their brightness as orbiting planets pass in front of them in so-called "transit" events.

    The orbiting observatory, launched in March, already detected the giant extrasolar planet HAT-P-7b within its first 10 days of taking data. The planet had previously been discovered by ground-based telescopes, but the observations showed Kepler works as expected.


    While ground-based observatories, and even some space telescopes, such as Spitzer and Hubble, can find Jupiter-sized extrasolar planets, Kepler is the first telescope aimed at detecting alien worlds closer to the size of our own home planet.

    One astronomer suggests that Kepler's capabilities may even be able to detect so-called "exo-moons."

    David Kipping of University College London has already devised a method for detecting exomoons but no-one was sure whether it could really be used with current technology. He and his team have now modeled the properties of the instruments on Kepler, simulating the expected signal strength that a habitable moon would generate.

    An exomoon's gravity tugs on the planet it orbits, making the planet wobble during its orbit around its host star. The resulting changes in the position and velocity of the planet should be detectable by Kepler through accurate timing of the transits.

    The scientists considered a wide range of possible planetary systems and found that a fluffy Saturn-like planet, which would be low in mass for its size, gives the best possible chance for detecting a moon, rather than a denser Jupiter-like world. This is because planets like Saturn are large – blocking out a lot of light as they pass in front of their star – but very light, meaning they will wobble much more than a heavy planet.

    If the Saturn-like planet is at the right distance from its star, then the temperature will allow liquid water to be stable on any sufficiently large moons in orbit around it. Such water-bearing moons might be habitable for life.

    "For the first time, we have demonstrated that potentially habitable moons up to hundreds of light years away may be detected with current instrumentation," Kipping said.

    Millions of moons possible
    The team found that habitable exomoons down to 0.2 times the mass of the Earth are readily detectable with Kepler.

    "As we ran the simulations, even we were surprised that moons as small as one-fifth of the Earth's mass could be spotted," Kipping said.


    While it is not known if habitable exomoons are common in the galaxy, the observatory could potentially look for Earth-mass habitable moons around 25,000 stars up to 500 light-years away from the sun. In the whole sky, there should be millions of stars which could be surveyed for habitable exomoons with present technology.

    "It seems probable that many thousands, possibly millions, of habitable exomoons exist in the Galaxy and now we can start to look for them," Kipping said.

    The team's findings will be detailed later this month in the journal Monthly Notices of the Royal Astronomical Society.
    © 2009 Space.com. All rights reserved. More from Space.com.
     
  5. 1.44

    1.44 Member of The Month SEPTEMBER 2009 Senior Member

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    Waiting for day when India launches it's own telescope.:)
     
  6. LETHALFORCE

    LETHALFORCE Moderator Moderator

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    Kepler Spacecraft Spots 5 New Exoplanets: Scientific American

    Kepler Spacecraft Spots 5 New Exoplanets
    NASA hopes that Kepler will eventually turn up habitable, Earth-like worlds
    By John Matson

    .

    A WARM APPETIZER: On the hunt for cool, low-mass planets, which may take years to identify, Kepler needed little time to find much more massive planets kept scorching hot by their host stars. Above, an artist's conception of one such "hot Jupiter."
    NASA/JPL-Caltech/T. Pyle (SSC)

    Astronomers have filled in more details in the picture of the Milky Way Galaxy, unveiling five previously unknown planets outside our solar system that were detected via early data from NASA's planet-seeking Kepler spacecraft. A team of researchers reported the planet findings Monday at a meeting of the American Astronomical Society and in a paper to be published online Thursday in Science.

    Kepler launched in March to seek out worlds like our own—terrestrial planets orbiting sunlike stars at a temperate distance where liquid water could persist. And although that search will likely take years, the spacecraft was able to pick out five larger, hotter planets in its first 43 days of observations.

    Trailing Earth in an orbit around the sun, Kepler monitors the brightness of about 150,000 stars, looking for periodic dimming that might be caused by a planet passing in front of its star. The spacecraft initially identified 175 possible planetary systems for follow-up observation from the ground, says Kepler co-investigator Natalie Batalha, a professor of physics and astronomy at San Jose State University.

    With 85 nights of observations on mid-size telescopes across the globe and 11 nights on one of the powerful 10-meter Keck telescopes atop Mauna Kea in Hawaii, the Kepler team thoroughly checked out 50 of those possible planetary systems, Batalha says. From the ground, the researchers looked for Doppler shifts in the suspect stars' light spectra that would reveal a gravitational wobble induced by an orbiting planet. Many were false positives, such as gravitationally bound binary stars eclipsing one another, but the five previously unknown planets emerged. As for the other 125 candidates, follow-up work is ongoing. "A bottleneck right now is having enough telescope time to follow up on all these interesting candidates that we have," Batalha says.

    The five planets in the new Kepler results are all giants, with masses ranging from about 25 to 670 Earths. (The least massive, Kepler 4b, is roughly 1.4 times the mass of Neptune.) They are scorching, too—each planet's host star is about as hot as the sun, but the Kepler planets' orbits hug their stars so tightly that they complete a revolution in less than five days. For comparison, Mercury, the innermost planet in the solar system, takes 88 days to circle the sun.

    The short orbital periods of the newfound planets enabled their detection from the small data set—each planet passed its star several times in the 43-day observation window, dimming the starlight by a small fraction with each orbit. Observing multiple orbits of cooler planets with longer orbital periods will take much more time. To find a true Earth analogue orbiting a sunlike star at about the same distance separating Earth from the sun—in other words, an Earth-size world with an orbital period of about one year—the Kepler team estimates that it will need about three years of observations from the spacecraft.

    To complicate matters further, a planet of roughly Earth size would dim its host star only slightly and would induce very little wobble in the star, making identification and follow-up confirmation more difficult.

    Habitable Earth-size planets might turn up sooner around smaller, cooler stars in Kepler's field of view, where water could persist on closer-orbiting planets that would complete laps around their host stars more quickly. But even so, exoplanet enthusiasts shouldn't expect pay dirt too soon—follow-up observations of any exo-Earth will be tricky and time-consuming. "The smaller the planet is, the harder it is to confirm," Batalha says. "It takes more telescope time. We'll be very careful with those."
     

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