For a few evenings around 28 February, every planet in the solar system will be visible in the night sky, thanks to a rare great planetary alignment. Here's how to make sure you don't miss this ...

Earth has a nearly circular orbit, but some planets outside our solar system, called exoplanets, have very elliptical orbits. UCLA astrophysicists have now measured the shape of the orbits of ...

As well as planets and moons, the solar system also contains dwarf planets, which are too small to be considered planets. The best known of these is Pluto, an ice dwarf that orbits far from the ...