News Astronomy

Kepler shows small exoplanets are either super-Earths or mini-Neptunes

Tally from the prolific space telescope adds 10 more potentially habitable rocky planets to count

Kepler-452b and Kepler-22b

PLANETARY COUSINS Planets may be lumped into two groups: smaller and rocky like Kepler-452b (left), or bigger and gassy like Kepler-22b (right).

W. Stenzel/NASA Ames

By Lisa Grossman

- More than 2 years ago

Small worlds come in two flavors.