Astronomers have identified a quartet of small rocky planets orbiting Barnard's star - one of our closest stellar neighbors - ...

Mars, Jupiter and Saturn are frequently seen in the night sky. But because Venus and Mercury orbit closer to the sun than ...

As the name suggests, retrograde refers to when a planet appears to go backward in its orbit as viewed from Earth.

That is because both Venus and Mercury orbit closer to the sun than Earth, meaning they orbit much quicker than other planets, according to NASA. When was the last time 6 planets aligned?

Mars, Jupiter and Saturn are frequently seen in the night sky. But because Venus and Mercury orbit closer to the sun than Earth, with smaller, faster orbits, it's more rare for them to make an ...

Mars, Jupiter and Saturn are frequently seen in the night sky; but because Venus and Mercury orbit closer to the sun than Earth, with smaller, faster orbits, it's rare for them to make an ...