Hot, rocky exoplanets are the scorched cores of former gas giants

The planets are nestled close to their stars, where stellar winds may have blown ancient atmospheres away

55 Cancri e

NOT LIKE HOME  Rocky super-Earth 55 Cancri e, seen in this artist’s illustration, is about Earth’s size, but a new study suggests it and other similar hot exoplanets probably formed in a completely different way than Earth did.

Hubble, ESA and M. Kornmesser

Earth may not provide the best blueprint for how rocky planets are born.