Jupiter-Like planet discovered
The planet, known as 51 Eridani b, is only 20 million years old, and could yield clues to the formation of our Solar System.
“This one is, in a lot of ways, the closest to Jupiter we’ve ever seen,” said study leader Bruce Macintosh, an astronomer at Stanford University.
The planet was found using the Gemini Planet Imager in Chile, which uses a novel approve to discover exoplanets.
Instead of looking for stars that dim as planets pass between them and Earth, like the Kepler space observatory does, it searches for light generated directly by the planet.
“To detect planets, Kepler sees their shadow,” Mr. Bruce Macintosh said in a statement. “The Gemini Planet Imager instead sees their glow, which we refer to as direct imaging.”
But what has scientists most excited is that, like Jupiter, 51 Eridani b has an atmosphere awash with methane. It’s the first time large amounts of methane have been directly detected in the atmosphere of an exoplanet.
It’s also large — about twice the mass of Jupiter — and relatively cool at 800 degrees Fahrenheit. (Planets as young as 51 Eridani b are often as hot as 1,200 degrees Fahrenheit).
“We have been searching for evidence of methane since the first exoplanet was discovered, as it implies conditions similar to what we see in the atmospheres of our own giant planets in the solar system. To have found such an extraordinary example of a methane-rich atmosphere so early in our survey with GPI is really encouraging,” said Mr. Macintosh.
The scientists detailed their findings online Aug. 13 in the journal Science.