|
NASA Scientists Detect Spectrum of Planets Orbiting Other Stars
February 23, 2007For the first time, scientists at Goddard have obtained a spectrum, or molecular fingerprint, of a planet orbiting another star. Using spectroscopy, scientists were able to identify silicon dust in clouds on a gas-giant planet called HD 209458b. That planet is located 150 light years from Earth.
"This first-of-its-kind measurement represents a significant advance in the field of extrasolar planetary science," said Jeremy Richardson, NASA Postdoctoral Fellow at NASA's Goddard Space Flight Center, Greenbelt, Md. Richardson and colleagues published their study in the Feb. 22 issue of Nature magazine.
One way in which scientists can study the properties of extrasolar planets is using spectroscopy, which refers to spreading light into its different colors (similar to a prism). For these observations, the team used NASA's Spitzer Space Telescope, which operates in the infrared.
The team took advantage of the unique geometry of this particular planetary system. It is a so-called "transiting planet," meaning that the planet crosses in front of its star as seen from Earth. By measuring the spectrum of the planet and star together, then subtracting the spectrum of the star alone (when the planet is hidden behind the star), scientists can figure out the spectrum of the planet.
Richardson and his co-authors found that the extrasolar planet's spectrum revealed the "signature" of silicate (an element found on Earth) dust in clouds high in the planet's atmosphere.
Although the scientists saw "spectral signatures" or identifiers that were related to clouds, they were surprised that they didn't see any signatures that showed there was water vapor. On Earth, clouds are composed primarily of water vapor.
Richardson said that planets similar to this one, often called "hot Jupiter" type planets because they are gaseous like Jupiter but very close to their parent stars (even closer than Mercury is to the sun), must contain water vapor.
"Since oxygen and hydrogen are such abundant molecules in the cosmos it is virtually impossible for water (as vapor, or steam) to be absent from the planet, Richardson said. "So. the water vapor must be hidden, probably by the same cloud layer that we detect in the spectrum."
Once more powerful infrared telescopes like the James Webb Space Telescope, slated for launch in 2013, are launched, and as smaller planets are detected, this technique may hold promise for detecting the signatures of life on hot Earth-like planets.
In addition to Richardson's team, two other independent groups also captured spectra of extrasolar planets. See http://www.spitzer.caltech.edu/Media/releases/ssc2007-04/ for details
NASA
The team took advantage of the unique geometry of this particular planetary system. It is a so-called "transiting planet," meaning that the planet crosses in front of its star as seen from Earth. By measuring the spectrum of the planet and star together, then subtracting the spectrum of the star alone (when the planet is hidden behind the star), scientists can figure out the spectrum of the planet.
Richardson and his co-authors found that the extrasolar planet's spectrum revealed the "signature" of silicate (an element found on Earth) dust in clouds high in the planet's atmosphere.
Although the scientists saw "spectral signatures" or identifiers that were related to clouds, they were surprised that they didn't see any signatures that showed there was water vapor. On Earth, clouds are composed primarily of water vapor.
Richardson said that planets similar to this one, often called "hot Jupiter" type planets because they are gaseous like Jupiter but very close to their parent stars (even closer than Mercury is to the sun), must contain water vapor.
"Since oxygen and hydrogen are such abundant molecules in the cosmos it is virtually impossible for water (as vapor, or steam) to be absent from the planet, Richardson said. "So. the water vapor must be hidden, probably by the same cloud layer that we detect in the spectrum."
Once more powerful infrared telescopes like the James Webb Space Telescope, slated for launch in 2013, are launched, and as smaller planets are detected, this technique may hold promise for detecting the signatures of life on hot Earth-like planets.
In addition to Richardson's team, two other independent groups also captured spectra of extrasolar planets. See http://www.spitzer.caltech.edu/Media/releases/ssc2007-04/ for details
NASA
Planets News and Current Planets Events RSSPhysicists create millimeter-sized 'Bohr atom'
Nearly a century after Danish physicist Niels Bohr offered his planet-like model of the hydrogen atom, a Rice University-led team of physicists has created giant, millimeter-sized atoms that resemble it more closely than any other experimental realization yet achieved.
Laser fluorescence could find life on Mars
A team of scientists from the United States and the United Kingdom has developed a technique using ultraviolet light to identify organic matter in soils that they say could be used to document the existence of life on Mars.
A Trio of Super-Earths
Today, at an international conference, a team of European astronomers announced a remarkable breakthrough in the field of extra-solar planets. Using the HARPS instrument at the ESO La Silla Observatory, they have found a triple system of super-Earths around the star HD 40307.
Mini subs to probe odd structures in BC lake
Single person submersibles have been called in to help scientists retrieve samples from a lake in northern British Columbia that may hold vital clues to the history of life on Earth and on other planets.
Scientists confirm that parts of earliest genetic material may have come from the stars
Scientists have confirmed for the first time that an important component of early genetic material which has been found in meteorite fragments is extraterrestrial in origin, in a paper published on 15 June 2008.
Plutoid chosen as name for Solar System objects like Pluto
Almost two years after the International Astronomical Union (IAU) General Assembly introduced the category of dwarf planets, the IAU, as promised, has decided on a name for transneptunian dwarf planets similar to Pluto.
NASA Scientists Pioneer Method for Making Giant Lunar Telescopes
Scientists working at NASA's Goddard Space Flight Center in Greenbelt, Md., have concocted an innovative recipe for giant telescope mirrors on the Moon. To make a mirror that dwarfs anything on Earth, just take a little bit of carbon, throw in some epoxy, and add lots of lunar dust.
Astonomers find tiny planet orbiting tiny star
An international team of astronomers led by David Bennett of the University of Notre Dame has discovered an extra-solar planet of about three Earth masses orbiting a star with a mass so low that its core may not be large enough to maintain nuclear reactions. The result was presented Monday (June 2) at the American Astronomical Society annual meeting in St. Louis.
Astronomers Weigh the Coldest Brown Dwarfs with Astronomy's Sharpest Eyes
Astronomers have used ultrasharp images obtained with the Keck Telescope and Hubble Space Telescope to determine for the first time the masses of the coldest class of "failed stars," a.k.a. brown dwarfs.
Where man boldly goes, bacteria follow
Life in outer space is an absolute certainty, and it is likely to be more familiar than we might think, according to an article in the May issue of Microbiology Today. Ever since the start of the space race we have sent more than just satellites and astronauts into space: spacecraft are not routinely decontaminated and are teeming with microbial life.
More Planets News Articles
 | The God Delusion by Richard Dawkins |
 | Anathem by Neal Stephenson |
 | Common Wealth: Economics for a Crowded Planet by Jeffrey D. Sachs |
 | The Ashes of Worlds (Saga of Seven Suns) by Kevin J. Anderson |
 | Old Man's War by John Scalzi |
 | Blue Planet in Green Shackles by Vaclav Klaus |
 | Our Dumb World: The Onion's Atlas of the Planet Earth, 73rd Edition by The Onion |
 | Incredible Hulk: Planet Hulk by Greg Pak |
 | The Wrinkle in Time Quintet Boxed Set (A Wrinkle in Time, A Wind in the Door, A Swiftly Tilting Planet, Many Waters, An Acceptable Time) by Madeleine L'Engle |
 | The Green Book: The Everyday Guide to Saving the Planet One Simple Step at a Time by Elizabeth Rogers, Thomas M. Kostigen |
| © 2008 BrightSurf.com |