An alternate explanation that fits the evidence is that Vesta was once part of a planet – but which planet that might been ...

These types of exoplanets are some of the most common in our galaxy - but they've remained mysterious until now.

Astronomer Eliza Kempton said that she had waited her "entire career" to peer into an atmosphere from this mysterious class of planets.

The number of known exoplanets seems to grow every day. Most of them are worlds completely unlike our own. But some get pretty close to something resembling home - and may someday become exactly that.