A new study of a forming planet shows it doesn't match the chemical makeup of its birth disk, challenging pas theories on how ...

Mars has two moons, Phobos and Deimos. Scientists still debate whether these came from asteroids that passed close into Mars' ...

Want to see Mars at its brightest in January? The best telescopes for seeing planets give you the clearest views of our celestial neighbors. The new year is a great time to test out your ...