The basic ingredients for life have been found around a second extrasolar planet, scientists reported Tuesday.
Although the planet itself is not habitable by life as we know it, the discovery could mean that the basic components of life are widespread in the atmospheres of many kinds of exoplanets.
The new find was made by training both the Hubble and Spitzer Space Telescopes on HD 209458b, a hot Jupiter that orbits very close to its sunlike star. It's located 150 light years away in the Pegasus constellation. In December of last year, Jet Propulsion Laboratory astronomer Mark Swain and his team found a similar Jupiter-like planet, HD 189733b, with carbon dioxide in its atmosphere.
"Detecting organic compounds in two exoplanets now raises the possibility that it will become commonplace to find planets with molecules that may be tied to life," Swain said in a press release.
The study of exoplanets has exploded since the first were discovered in the early 1990s. Just Monday, astronomers announced the discovery of 32 new exoplanets. And detections aren't just growing in number, but sophistication as well. Exoplanetary scientists are learning more and more about the systems in which the planets are found.
Early exoplanet discoveries were made using a variety of techniques, but primarily by measuring the "wobble" a star exhibits in the presence of another massive body. In more recent years, scientists have looked for "transiting" planets, which pass in front of and behind their stars. Far more can be learned about these celestial bodies.
When an exoplanet passes in front of its star, scientists are able to translate small differences in the color of the light arriving at Earth into a chemical signature for the planet's atmosphere. For example, HD 209458b has water and carbon dioxide, just like HD 189733b, but it's also got a lot more methane.
"The high methane abundance is telling us something," said Swain. "It could mean there was something special about the formation of this planet."
Planetary spectroscopy is easiest to do for systems in which a large exoplanet orbits very close to its home star. With smaller planets orbiting farther from their star, it is harder to detect the minute changes in the star's light.
Though the Kepler Space Telescope is likely to find many Earth-like planets, it could be a decade before we have the technological capability to definitively detect a rocky planet with an atmosphere and orbit like ours, an Earth twin.
Rendering: NASA/JPL-Caltech/T. Pyle (SSC)
See Also:
- Hubble Detects First Organic Molecule Around Exoplanet
- Life Hunters Target Methane Plumes on Mars
- Key Molecule for Life Found in Habitable Region of the Galaxy ...
- 'She Lives! Let's Go Find Planets!': Telescope Launch Successful ...
- Kepler Shows Exoplanet Is Unlike Anything in Our Solar System ...
- Aack, No Brakes! Giant New Exoplanet Goes the Wrong Way
- Smallest Exoplanet Is Most Earth-like Yet
- Astronomers Find Hidden Exoplanet in Hubble's Dustbin
- At Last! First Real Evidence for a Rocky Exoplanet
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