Wed, December 10, 2008
WASHINGTON – Carbon dioxide has been seen on a hot planet outside our solar system -- another piece of evidence supporting the possibility that life could develop elsewhere, astronomers said on Tuesday.
NASA said its Hubble Space Telescope has discovered carbon dioxide in the atmosphere of "hot Jupiter" planet HD 189733b, which orbits a nearby star 63 light-years from Earth.
The planet is itself too hot to support life -- its surface is about 1,800 degrees F (1,000 degrees C).
But the astronomers said the observations are a proof-of-concept demonstration that the basic chemistry for life can be measured on planets orbiting other stars.
In March, they found the ingredients for methane on the planet, one of about 300 planets so far found circling stars other than our own. Evidence has also been found for water vapor there.
"These atmospheric studies will begin to determine the compositions and chemical processes operating on distant worlds orbiting other stars," said Eric Smith, Hubble Space Telescope program scientist at NASA.
Mark Swain of NASA's Jet Propulsion Laboratory in Pasadena, California used Hubble's near-infrared camera and multi-object spectrometer to study infrared light from the planet.
He was able to identify carbon dioxide and carbon monoxide, which absorb certain wavelengths of near-infrared radiation.
"The carbon dioxide is the main reason for the excitement because, under the right circumstances, it could have a connection to biological activity as it does on Earth," Swain said in a statement.
"The very fact we are able to detect it and estimate its abundance is significant for the long-term effort of characterizing planets to find out what they are made of and if they could be a possible host for life."
(Agencies)
