We discovered an atmosphere on an Earth-like planet in a star's habitable zone

It's a first that includes ingredients for life itself — and it challenges assumptions we've had about other planets.

Ada Wood / Science - Space / The Weather Channel 

Astronomers have detected an atmosphere on the Earth‑like exoplanet LHS 1140 b, located in its star’s habitable zone about 48 light‑years from Earth, marking the first clear evidence of a rocky planet beyond the Solar System retaining an atmosphere over time.

Key points:

LHS 1140 b is an Earth‑size planet about 5.6 times the mass of Earth orbiting a small, cool red dwarf star.

The planet lies in the habitable zone, receiving less than half the sunlight Earth receives.

Scientists identified the atmosphere by detecting helium gas leaking into space during a transit observation.

The detection was made by observing a dip in the star’s infrared light at the wavelength where helium absorbs.

Before accounting for the atmosphere, the planet’s estimated surface temperature was roughly –53 °F. Read more, see photos and video here.