During the last decade, we have witnessed the first discoveries of planets that orbit around stars other than the Sun.

These remarkable discoveries were difficult because planets shine by the light reflected from their parent star, and so distant planets are generally very faint (and lost in the glare of the nearby star).

These distant planets are detected by their gravitational pull on the parent star (causing a periodic wobble in the motion of the star). These detection methods will generally find massive planets (those like Jupiter with significant gravitational pull), not low mass planets (like Earth).

The kinds of planets discovered have been surprising.