Phobos and Deimos (5)

1 Name: Donald : 2011-04-03 17:15 ID:aILAwJXB

If Pluto is no longer considered a planet, then can Phobos and Deimos actually qualify as moons? They are both under 25 miles in diameter. Quite a few of the orbiting of the outer gas giants are also small in size and should not be considered "moons" but should be demoted to something like "moonlets".

2 Name: Anonymous Scientist : 2011-04-04 11:15 ID:aFrLOlVf

Huh. It's a point to be made, I guess.

Wikipedia still says moons, but wikipedia also has a Sonic the Hedgehog fetish. There's also some mention of moonlets, but only in reference to very tiny mostly unobserved things. Anxiously awaiting the disamiguation page featuring Moonlet (Band).

As far as I can tell the definition of a planet is round, orbits a star, and was not discovered by an American. Not sure if there's a standard definition for a moon yet. Let an American discover something tiny in orbit around a planet and we'll get that squared away in a hurry!

3 Name: Anonymous Scientist : 2011-04-06 13:24 ID:Kao18DDv

Even being under 25km in diameter, they are still noteworthy natural satellites in a planet's orbit. Without them we wouldn't have Doom so I think they deserve their prestige.

4 Name: Anonymous Scientist : 2011-04-28 21:44 ID:jFrCp4ZF

"A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, dwarf planets, and minor planets."
So there's no restriction on size or shape.

5 Name: Anonymous Scientist : 2011-04-28 21:46 ID:jFrCp4ZF

Note that Dactyl orbiting Ida asteroid is considered a moon too.

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