There are eight official planets (sorry, Pluto) in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and ...
Charon is large in size relative to Pluto, and is locked in a tight orbit with the dwarf planet. A new simulation suggests how it ended up there.
As Mars approaches opposition this month, it will become a dazzling spectacle in the night sky. See it at its best now, or ...
Alinda is one of the five largest near-Earth asteroids, coming closer than 9.3 million miles until the year 2200.