What terrestrial planet is smaller than the Solar System's two biggest natural satellites, Ganymede and Titan?

Mercury, named after the Roman deity of trade, is the Solar System's smallest planet. At the same time, it's also the fastest, moving at roughly 29 miles per second. A planet's speed increases as it gets closer to the sun, which is why Mercury has the shortest year of all the planets, only 88 days.

Asked by Vasilii Kulev · Last updated 4 years ago · 1.9K views · SOURCE