Chicago (IL) – NASA today said that its Hubble Space Telescope (HST) has identified
carbon dioxide in the atmosphere of a planet orbiting another star. The
discovery surrounding HD 189733b is an important step in finding
biotracers of extraterrestrial life, but the planet itself is too hot to support life as we know it.
But even if HD 189733b cannot support life, the Hubble finding is considered a breakthrough discovery and serve as a proof-of-concept demonstration that the basic chemistry for life in fact can be measured on planets orbiting other stars. This means, at least in theory, that Hubble would be able to find life-supporting planets. Researchers now hope that the identification of organic by-products will lead “someday” to evidence of life beyond Earth.
“Hubble was conceived primarily for observations of the distant universe, yet it is opening a new era of astrophysics and comparative planetary science,” said Eric Smith, Hubble Space Telescope program scientist at NASA Headquarters in Washington. “These atmospheric studies will begin to determine the compositions and chemical processes operating on distant worlds orbiting other stars. The future for this newly opened frontier of science is extremely promising as we expect to discover many more molecules in exoplanet atmospheres.”
HD 189733b isn’t exactly close to Earth, but 63 light years away. Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., used Hubble’s near infrared camera and multi-object spectrometer to study infrared light emitted from the planet. The fact that gases in the planet’s atmosphere absorb certain wavelengths of light from the planet’s hot glowing interior, enabled Swain and his team to identify carbon dioxide and carbon monoxide. NASA said that this project was the first of its kind to result in obtaining a near-infrared emission spectrum for an exoplanet.
“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. “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.”
However, the actual existence of life, at least as far as we know it, on HD 189733b is not very likely. NASA has been studying the planet for several years and announced in May of 2007 that it is actually among the hottest of the more than 200 extrasolar planets known today. The surface temperature is believed to be between 1200 and 1700 degrees F (650 – 930 degrees C). Additionally, NASA scientists said that the extreme conditions on the planet are worsened by “fierce winds”.
Nevertheless, it is fascinating to see that scientists can detect organic molecules on a planet that are 63 light years away. In March of this year, HST identified methane in HD 189733b’s atmosphere.