Gliese 3470 is bigger than Earth but smaller than Neptune. (Representational Image)
In a first, NASA scientists have revealed the atmosphere of a planet outside our solar system using its Sptitzer and Hubble space telescopes. The planet, which the space agency believes is not found in our solar system, has been named Gliese 3470 b (GJ 3470 b). The planet is believed to be a cross between Earth and Neptune and has a hydrogen-and-helium atmosphere.
With 12.6 Earth masses, Gliese 3470 is bigger than Earth but smaller than Neptune, which has 17 Earth masses. NASA says such planets are common around other stars and it will study it to uncover clues about its nature and origin.
“This is a big discovery from the planet-formation perspective. The planet orbits very close to the star and is far less massive than Jupiter -- 318 times Earth’s mass—but has managed to accrete the primordial hydrogen/helium atmosphere that is largely ‘unpolluted’ by heavier elements,” PTI quoted Bjorn Benneke of the University of Montreal as saying.
He said that currently there is no other planet like GJ 3470 b in the solar system, which makes it striking. Astronomers will now carry out a first-of-a-kind study on GJ 3470 b’s atmosphere through combined multi-wavelength capabilities of NASA’s Hubble and Spitzer space telescopes. The atmosphere of GJ 3470 b turned out to be mostly clear, with only thin hazes, enabling the scientists to probe deep into the atmosphere.
“We expected an atmosphere strongly enriched in heavier elements like oxygen and carbon which are forming abundant water vapour and methane gas, similar to what we see on Neptune… Instead, we found an atmosphere that is so poor in heavy elements that its composition resembles the hydrogen/helium-rich composition of the Sun” Benneke added.