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This article should be called "Astronomers actually redefine the term moon" If this is the definition, then lets also report that Saturn now has a gazillion mo
by moocow01 15y ago
This article should be called "Astronomers actually redefine the term moon"
If this is the definition, then lets also report that Saturn now has a gazillion moons.
- Someone 15y agoWe do. See http://en.wikipedia.org/wiki/Moons_of_Saturn http://en.wikipedia.org/wiki/Moons_of_Saturn
- maaku 15y agoI think he's referring to Saturn's rings, which is largly composed of objects like the “moon” in this article.
- white_raven 15y agoyea but saturn's rings are made of ice, moons and planets are made of rock just like asteroids not ice like comets.
- joshAg 15y agowhat's the difference between rock and ice? is there a boundary where if the melting point is below a certain value then the substance is ice, and if it's above that value it's rock? it's not like rock can't melt in the right circumstances.
- waqf 15y agoIce is made of small molecules like water, methane or carbon dioxide.
- joshAg 15y agois there a concrete cutoff or shades of grey?
- maaku 15y agoI think what the GP is getting at is the chemical difference of ionic minerals (rock) vs amorphous collections of molecular compounds (i.e. water or methane ice). There is a categorical difference between the two chemically, although as an aside their properties in micro-gravity and the cold vacuum of the outer solar system are quite different from what you might have learned in your chemistry class.
- maaku 15y agoSaturn's rings are made of the exact same stuff as its moons, because that's what they are. One or more of Saturn's moons broke up millions of years ago under gravitational/tidal forces, and over time the debree spread out into a ring. And BTW, there are plenty of examples of moons made of ice, and at the temperatures of the outer solar system ice can be harder than rock (and BTW, Neptune and Uranus are called "ice giants"--care to guess why?).