Jupiter
Saturn is known for its rings as well as it have 62 Natural Satellites.
As far as is known in mid-2011, that would be Jupiter.
Without checking the orbital inclinations of all the known planetary satellites, I'll take a rough guess that it's nominally the planet with the most known satellites, which is Jupiter, with at least 63 satellites presently known. If you want to go to the extreme, you might say that each and every stone in the rings of Saturn can certainly pass through the planet's shadow, causing a 'calcular eclipse', and there are billions of those.
jupiter. it has 64 known satellites
Planet Saturn has 62 known moons of which 53 are named. Of course, the famous rings are made up of debris of former satellites or moons.
jupiter has the maximum number of satellites.... of almost 63 moons
Jupiter
There are no known satellites of Mercury.
Venus has no known natural satellites (moons).
These are known as moons. Natural satellites that are in orbit around a larger planet.
Jupiter
Saturn is known for its rings as well as it have 62 Natural Satellites.
Venus is the biggest planet in our solar system that has no known satellites (moons).
I don't know of any planet with exactly 21 known moons. The best answer is probably "Uranus" with 27 moons (natural satellites).
As far as we know now, and we're pretty sure, Jupiter does. About 65 of them are known for Jupiter now.
100
Mercury and Venus have no known natural satellites (or moons).