How Bizarre Astronomy

Big exoplanet may be surrounded by helium

No hydrogen found around Neptune-sized planet

helium-rich skies

SQUEAKY PLANET  A world with helium-rich skies (illustrated) might be blanketed in white or gray clouds, researchers report.

JPL-Caltech/NASA

By Christopher Crockett

- More than 2 years ago

The party balloon industry could make a killing on an exoplanet such as GJ 436b, a broiling Neptune-sized world whose atmosphere might contain mostly helium.