Mars has two moons, but they're not quite like Earth's moon. That's raised a lot of questions about where they're from, ...

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 ...

The moon Phobos has a mysterious origin but a certain expiration date. Phobos, one of Mars' moons, has an uncertain origin, but its surface grooves show that tidal forces are pulling it apart. In time ...

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