Satellite Smackdown — Which Moon is the Solar System's Awesomest?S

A little while back, io9er Ed said Titan was "The Awesomest Moon in the Solar System." Well where I come from, them's fightin' words. What about Earth's Moon? Mars' Phobos? Europa?? There are boatloads of kickass moons in the solar system. We break down ten contenders in a highly scientific chart to settle this debate, once and for all. [click chart to enlarge, or click here to see full chart]

Crowning a moon champion ain't as easy as it seems when Saturn alone has 59 of them. Fortunately the field got smaller when we considered five key points all moons should have on their resumes. It may be hard to stomach having Charon up there — it's questionable that it's even a moon — but someone had to be the goat.

And now, the winners in the individual categories:

BEST FEATURE NAME: Despite tons of creative feature names, Europa wins by a wide margin with Rathmore Chaos. It sounds like a level of Hell from Dante's Inferno, but like most of the outer system, the Chaos is a cold place. In fact it's a jumble of broken up ice that's evidence of the moon's active ice tectonics...and maybe a liquid water ocean below.

POTENTIAL FOR COLONIZATION: Phobos gave Earth's Luna a run for it's money; it's low gravity and proximity to the Red Planet make it worthy of it's full score. But in the end the deck's stacked against the Martian moon — the stated goal for NASA's next generation of manned spaceflight is to return to the moon...to stay.

ACTIVE GEOLOGY: This is a toughy. Uranus' moon Miranda doesn't have active geology, but scientists speculate that the whole moon may have been obliterated by impacts, then reassembled itself. You know, like T-1000 in Terminator 2. Charon, Triton, and Enceladus all look like they've got actively erupting cryovolcanoes of frigid ammonia, water, or liquid nitrogen which is cool, but it knocks Titan down a notch in uniqueness. Jupiter's Io wins for it's self sacrifice though; riddled with volcanoes, the firey moon is literally gutting itself, spewing 1 ton of sulfur dioxide into space every second.

MOVIE/BOOK: The hands-down winner is Earth's Moon, which has been in books and movies since the art forms were invented. It's hardly a fair fight, so the prize goes to Jupiter's Ganymede. The largest moon in the solar system (that's right, bigger than Titan!), it haunts tons of Philip K. Dick's books.

POTENTIAL FOR LIFE: Cryovolcanoes are going off all over the solar system's icy moons, and where there are volcanoes, there's liquid. Most of the liquid is in the form of methane, ammonia, nitrogen, or some other substance that Earth-life wouldn't want to swim in, but who knows what sort of strange aliens could be out there?

That said, Europa's icy shell is made of old-fashioned H2O, and features like Rathmore Chaos look a lot like shifting pack ice here on Earth, which floats on a big ocean of salty water, which in turn contains tons of critters. There's a good chance the same is true on Europa, meaning....

the prize for THE OVERALL AWESOMEST MOON IN THE SOLAR SYSTEM goes to EUROPA!!! Honorable mention to TItan for a strong showing, but it just goes to show...don't mess with the moon with the water oceans under the ice!



Sources: Lunar and Planetary Institute

The Cascadia Astrobiology Institute

Science Direct

WIkipedia

The Nine Planets Solar System Tour