Does our Solar System have 9 planets or only 8? Astronomers have gone back and forth on that a lot, with Pluto now being classified as a dwarf planet. However, out beyond Neptune there could be ...

Scientists at NASA for the first time have been able to observe the make up of Pluto and other small and icy celestial bodies ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

For the first time, astronomers have imaged dozens of belts around nearby stars where comets and tiny pebbles within them are ...

Charon and Earth’s moon are both a large fraction of the size of the main body they orbit, which is unlike other smaller moons orbiting planets throughout our solar system. (Pluto has four ...

Take advantage of a special 6-7 planet alignment from Earth's perspective. Planets 'line up' in the skies over California in ...

In August 2006, the International Astronomical Union made the controversial, but correct, decision to demote Pluto from its ...

Charon is half the size of Pluto, “making it the largest known moon relative to its parent planet in our solar system,” NASA notes. So how did Pluto get its chonky companion? A new study ...

Eons ago, in the frigid depths of our solar system, a dramatic collision ... the importance of this structural integrity Pluto-Charon system. "Pluto and Charon are different – they're smaller ...