Two Best Friends | What You Should Know about The Red Planet

Two Best Friends

In 1877, American astronomer Asaph Hall, discovered that Mars has two travelling companions, Phobos and Deimos, two small satellites that orbit very close to the planet’s surface. Phobos travels at a distance of 9,000 km and has a radius of 11 km and a mass of 1.08e16 kg., while Deimos is at a distance of 23 km and has a radius of 6 km and a mass 1.80e15 kg.

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