Six planets in the solar system have at least one moon. Both Earth and Mars are toward the lower end of the lunar count, as our home planet only has one moon, and Mars has two. But not all moons share ...

The two small moons of Mars, Phobos (about 22km in diameter) and Deimos (about 13km in diameter), have been puzzling scientists for decades, with their origin remaining a matter of debate. Some have ...

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 ...

Thin layers of sedimentary rock in Mars’s Gale Crater suggest that the planet once had a moon much larger than the two that ...

Phobos is the larger and innermost of Mars' two moons, and it's a fascinating celestial body. It's small, irregularly shaped, and orbiting just about 6,000 kilometers above the surface of the Red ...

This has been a most interesting year to follow Mars. If you've been monitoring the Red Planet since the start of 2025, you have no doubt noted the dramatic change in its brightness as well as the ...

The new moon on Aug. 23 at 2:06 a.m. EDT (0606 UTC) is also a black moon, defined as the third new moon in a season that will see four new moons. Three days later, the moon will make a close pass to ...