One summer night in 1877, American astronomer Asaph Hall was looking through his telescope in Washington, D.C. Mars was at its closest point to Earth in its orbit, and Hall had one question on his ...

Earth's moon orbits at an average distance of 384,400km (238,855 miles), but the scale of the impact that ultimately sparked its formation was much grander than the asteroid that formed Phobos and ...

How "asteroid detectives" protect Earth from potential impacts 03:15. A space probe flying past Mars captured images of the red planet's small, mysterious moon.

Mars' Deimos moon, captured by NASA's Perseverance rover. NASA Once in ... Earth’s next door neighbor orbits at a far greater distance of about 238,855 miles (384,400 kilometers).

The moon and Mars will share a close approach tonight (Nov. 20) during a conjunction as the two visit the Cancer constellation, ... Mars orbits the sun on a much more distant path than Earth.

Mars will seem to disappear behind the full wolf moon Monday for many sky-gazers. Throughout January, also look up to see Venus, Saturn and Jupiter in the night sky.

This month will usher in two separate conjunctions — one between the moon and a rarely-visible Mercury, and another between the moon and Mars.

A moon is defined as any naturally-formed body that permanently orbits a planet. But because of their irregular shape and miniature size, many scientists say that Phobos and Deimos look more like ...