Naturally, we think that finding another Earth-like planet is identifying a site that's at least friendly here for the evolution of life. The primary goal of the Kepler mission is to statistically assess the occurrence of these small terrestrial worlds.

It can be very hard to know the history of a particular star, but once in a while, we get lucky and find stars with chemical compositions that likely came from in-falling planets.

There may be hundreds of small seed planets - or planetesimals - which grow in the disk of matter around a star.

Debra Fischer Quotes