New Ring Discovered Around Saturn
HunahpuMonkey writes "BBC News is reporting that 'scientists using the Cassini probe have found a new ring and one, possibly two, new objects orbiting Saturn.' The article also notes that the discoveries are in the planet's contorted F-ring region. The ring of new material seems to be associated with Saturn's moon Atlas."
There's a good article here about what exactly makes up a moon. I can tell you its not about gravity since basically every object with mass has gravity.
"satellite" means orbiting a planet.
"moon" means natural satellite.
"Moon" means Earth's moon.