Helium detected in exoplanet atmosphere for the first time
Helium, the second most common element in the universe, has been successfully found in the atmosphere of a planet beyond the solar system for the first time. Using the Hubble Space Telescope, astronomers discovered evidence of the inert gas on exoplanet WASP-107b, 200 light-years from Earth. Helium was first detected as a yellow spectral line signature in sunlight in 1868.