Scientists find a cloudless 'hot Jupiter' exoplanet with a four-day year

It could shed new light on planet formation.

M. Weiss/CfA

Astronomers have found another strange planet that could expand our understanding of the cosmos. Gizmodo reports that a team at Harvard and Smithsonian’s Center for Astrophysics has spotted a gas giant 575 light years away, WASP-62b, that’s not only in an extremely close 4.5-day orbit (making it a “hot Jupiter”), but has no clouds. It’s just the second time any researchers have located a cloudless exoplanet, and they’re believed to be rare as a whole — less than 7 percent of exoplanets.

Scientists first detected WASP-62b in 2012, but it wasn’t until recently that they got to study its atmosphere. Study lead Munazza Alam used spectroscopic observation from the Hubble Space Telescope to discover the strong presence of sodium, an element that would be obscured if there were clouds in the planet’s atmosphere. Astronomers typically get only small clues that sodium is present, so this was “smoking gun evidence” of a cloudless planet, according to Alam.

The CfA team hopes the upcoming James Webb Space Telescope will provide the added resolution and precision needed to further study the planet and find elements like silicon. That, in turn, could help understand how these planets formed and whether there were any differences from cloud-laden worlds. While this kind of exoplanet is uncommon, it might change thinking about planets as a whole.