Scientists find small moon hidden in one of Saturn's rings.

Scientists have found a new moon hidden in one of Saturn's dazzling outer rings. The international Cassini spacecraft spotted the moon, which measures about a third of a mile wide. The discovery was announced Tuesday in a notice by the International Astronomical Union.



http://news.yahoo.com/s/ap/20090303/ap_on_sc/sci_saturn_moon

I wonder what the characteristics are needed to be classified as a moon.

As in, let's look at it again in 100 million years.

Or a cow jumping over it?

It begs the next question though, what's the difference between a satellite and a moon?

A satellite is any object or system in free-fall motion with a locus centering on a single astronomical object. Under this definition, all the planets, asteroids, comets, etc. are satellites of the Sun. The Moon and the artificial objects humans have put in orbit around the Earth are all satellites of the Earth, Deimos and Phobos are satellites of Mars, every grain of dust in Saturn's rings and the Cassini probe are satellites of Saturn, etc. Charon is not a satellite of Pluto, as neither body orbits the other; they both orbit a common center of gravity, which would make the Pluto-Charon system a satellite of the Sun.

To be classed as a moon, a satellite would have to meet these requirements, similar to the ones that define a planet:

* It is a natural satellite.

* It orbits a planet, not a star, dwarf planet or other body.

* It has sufficient mass so as to assume a nearly round shape.

* It has "cleared the neighborhood" around its orbit.

Under this definition, several satellites currently classed as moons would get downgraded, as they are not roundish.

how would you classify an orbiting satellite(or moon) as a natural satellite when the various theories of our own moon would not fit this model.

For me the difference between a moon and a satellite is size and after your interesting 3rd definition, shape. I also think that gravitational fields should be use to distinguish the differences between them.

That it was likely formed as "splash back" from a massive impact billions of years ago is irrelevant: it is still a natural body, not an artificial one like Sputnik or Cassini. Unless a tiny band of conspiracy theorists are right about the Antareans, of course.

And what about gravitational fields should be used?

the strength of their gravitational field could be used as a measuring stick, imho.

there are any number of satellites. Man made and natural.
Only one Moon.

I can see how all of this can become terribly confusing. ;)

Like Earth, Mars, Venus etcetera.
I know it is confusing, but there you go.
Cheers

It's Luna. "Moon" in not a name.

The correct statements are "There is only one Sun" and
"There is only one Moon" but there are many suns and
many moons. (Hint: capital letters mean something ...).

I know it is confusing but the English language is good like that ...

Cheers.