What is the Smallest Moon in the Solar System?
Written by Fraser Cain
Wondering what is the smallest moon in the Solar System? It's a bit of a difficult question because it's really hard to define where you draw the line between moon and a part of a ring. Saturn even has tiny moonlets; they're not quite moons, and they're not quite rings.
Jupiter has many moons which are less than 10 km across. In fact, it has several that are only 2 km across. But two moons, S/2003 J 9 and S/2003 J 12 are only 1 km across. This makes them the smallest moons in the Solar System.
NASA's Cassini spacecraft has discovered several "moonlets". These small chunks of ice only a few hundred meters across. They're so small the spacecraft wasn't able to see them directly, but only detect them by the wake they leave as they pass through Saturn's rings.
If astronomers reclassify these moonlets as actual moons, they would become the smallest moons in the Solar System.
Wondering what's the biggest moon in the Solar System, and here's how many moons there are in the whole Solar System.
We have recorded a whole series of podcasts about the Solar System at Astronomy Cast. Check them out here.
Filed under: Astronomy
