First search for atmospheres around Earth-sized exoplanets

NASA’s Hubble telescope has made the first atmospheric study of two Earth-sized planets outside our Solar System.
By AG Staff Writer / NASA July 21, 2016 Reading Time: < 1 Print this page

ASTRONOMER’S USING NASA’s Hubble telescope have conducted the first search for atmospheres around two temperate, Earth-sized planets outside our Solar System – and found indications that increase their chances of habitability.

The astronomers looked at two exoplanets orbiting a red swarf star in the constellation Aquarius, about 40 light-years away. They discovered the two planets, called TRAPPIST-1b and TRAPPIST-1c, are unlikely to have “puffy, hydrogen-dominated” atmospheres usually found on gaseous worlds.

“The lack of a smothering hydrogen-helium envelope increases the chances for habitability on these planets,” said Nikole Lewis of the Space Telescope Science Institute (STScI) in Baltimore, USA.

“If they had a significant hydrogen-helium envelope, there is no chance that either one of them could potentially support life because the dense atmosphere would act like a greenhouse.”

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The scientists observed the two planets using near-infrared light using Hubble’s Wide Field Camera 3. They used a technique called spectroscopy to ‘decode’ the light and reveal clues about the chemical makeup of an astmosphere. 

While the exact content of the atmospheres is unknown and will have to await further observations, the low concentration of hydrogen and helium has scientists excited about the implications.

“These initial Hubble observations are a promising first step in learning more about these nearby worlds, whether they could be rocky like Earth, and whether they could sustain life,” says Geoff Yoder, acting associate administrator for NASA’s Science Mission Directorate in Washington, USA.

“This is an exciting time for NASA and exoplanet research.”

Source: NASA