http://www.playfuls.com
NASA scientists were able to analyze the makeup of distant planets in other solar systems using a technique that could one day be used to find life on other planets, astronomers said Wednesday.
Teams of scientists used the space-based Spitzer infrared telescope to measure the spectra, or light emissions, of two giant, gaseous planets, trillions of kilometres away from Earth. By breaking the light given off by the planets into different wavelengths, the scientists could analyze their chemical composition.
The two planets - known as HD 189733b, 63
light years away in the constellation Vulpecula, and HD 209458b, 154
light years away in the constellation Pegasus - are so-called
hot-Jupiters, gaseous planets like Jupiter, but located much closer to
their suns.
At a teleconference, scientists involved in the project said that
more powerful telescopes could likely use the same technique to examine
smaller, rocky planets, which could be more Earth-like.
Mark Swain, a research scientist at NASA's Jet Propulsion
Laboratory, said that the results were a "very important stepping
stone" for drawing conclusions about other types of planets that could
be hospitable for life.
"This is really a dress rehearsal for what we can expect in the future," Swain said.
The scientists had believed they would find water in the planets'
atmospheres, but their analysis came up short on answering the water
question.
Because hot-Jupiters are believed to contain water in their
atmospheres, the astronomers said that several theories could account
for the lack of water-based steam on the estimated 815-degree planets.
One explanation could be that the water molecules were obscured
by dusty clouds. Another option is that other molecules absorbed the
light given off by water molecules, scientists said.
"Just because we don't see it doesn't mean it's not there," NASA scientist Jeremy Richardson said.
The teams said they will continue to refine their techniques to
further examine the planets. They may find the elusive water later.
Even without water, they can estimate that "the weather today on
209458 is hot, dry, probably cloudy with a chance of wind," Swain said.
The emerging ability to examine distant planets' spectra and
search for water could eventually help astrobiologists pinpoint life on
other planets.
"The mantra is look for water," astronomer Alan Boss said of the hunt for extraterrestrial life.
The results will be published in Nature and the Astrophysical Journal Letters.
By Anne K. Walters, Dpa
© 2007 DPA
See also:
|
