Dear Tom,
The moon revolves around the Earth, and other planets in the solar system
have a few moons. Do any of those moons have their own moons?
Robert Miller, Chicago
Dear Robert,
You might be surprised to learn that the population of moons in our solar
system is considerably larger than "a few." The Earth has one, but at least
60 moons are in orbit around Jupiter, and Saturn boasts a minimum of 52.
We suggested to astronomer Dan Joyce of the Cernan Earth and Space Center
at Triton College that it would seem theoretically possible for moons to
have moons, but conflicting gravitational fields might pull them out of
orbit.
Joyce responded, "Yes, it's theoretically possible for moons to have moons,
but no, there are none known. By the way, our own moon does have artificial
satellites that are not in any danger of being yanked out of orbit any time
soon."
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
