big things

[low_delta]

Ganymede, Jupiter's larget moon, is the largest moon in the solar system, and larger than Mercury. It's the only planetary satellite that can be seen with the naked eye (edit: aside from our moon, duh). It's the only moon with a significant magnetic field.

Titan, Saturn's largest moon, is the second largest moon in the solar system, and is also larger than Mercury. It's the only moon in our solar system to have a dense atmosphere. Because of that atmosphere, it had been thought to be larger than Ganymede.

Jupiter's Callisto, the third largest moon, is heavily cratered. It's 40% ice, and 60% rock and iron.

Moon number four, Jupiter's Io, has almost no craters, due to intense volcanic activity. It is the most volcanically active body in the Solar System.

The fifth largest moon is Earth's moon. Unlike most satellites of other planets, the Moon orbits near the ecliptic (Earth's plane of orbit) and not the Earth's equatorial plane.

The sixth largest moon is Jupiter's Europa. It is the smoothest object in the solar system. Its outer layer is 100km of water, the topmost of which is frozen.

Io, Europa and Ganymede are locked into Laplace-resonant orbits such that Io orbits twice for each orbit of Europa, which in turn orbits twice for each orbit of Ganymede. Callisto will eventually join this resonance relationship as well.

Like Earth's moon, These four largest moons of Jupiter are tidally locked to the planet, with one hemisphere of the satellite constantly facing the planet.

Comments

[rivendweller.livejournal.com]

Very interesting post. I've read speculation that Europa might have primitive live beneath all that frozen water.

I love the photos of Jupiter's moons taken by the Voyager probe so many years ago.

[banana.livejournal.com]

> Ganymede [is] the only planetary satellite that can be seen with the naked eye.
Hmm - there's another fairly obvious one.

[low-delta.livejournal.com]

Hahaha! Good catch.

[ravengirl.livejournal.com]

calisto is my favorite of jupiter's moons. it's very photogenic, yes.

[low-delta.livejournal.com]

Yes it is. Europa has a good look too. It's very... impressionist, compared to Callisto's photorealism. Europa looks airbrushed. Like it belongs on the cover of an old science fiction paperback.