For centuries, planets beyond our solar system—called exoplanets—existed only in theory and science fiction ... star passes directly in front of a background star, as seen from Earth.

Many of you, like myself, were probably taught in grade school that Pluto was the ninth planet in our solar system, and, until 2006, this was accepted as fact. I’ll return to Pluto’s discovery, and ...

Scientists have discovered a new planet, Enaiposha, that defies existing planetary classifications. Found 47 light-years away ...