This is Europa.  Europa is the most interesting of Jupiter’s 67 moons.  Io is the second coolest, if you happen to be wondering, and S/2003 J 2, which has a dumb name and is only two kilometers wide, is the least interesting.

Europa has at some point (and that point may be now) harbored life.  Yes, I’m phrasing it that definitively.  I don’t care.  I’m a rebel, dammit!  Plus I’m right.  Do I mean, like, little green dudes who might eat us?  No; probably bacteria of some sort, although something more complicated is certainly possible.  But Europa is basically a giant ball of ice with a water ocean underneath it.  The surface features, you see, change on a fairly regular basis, and Europa is the flattest object in the solar system– it doesn’t really appear to have a lot of craters.

That no craters thing is a huge key to the existence of the ocean, see; the idea is that that frozen surface is continually cracking (being as close to Jupiter as it is means that the planet’s gravity is wreaking havoc with Europa’s surface) and the liquid water underneath is coming up and re-freezing the surface.  Which, as you know if you’ve ever seen ice, tends to create a pretty flat surface.

Our experiences on Earth have taught us just how hardy life is.  Basically, anywhere there’s water, there’s life.  Hell, even in places where there’s barely any water, there’s still life.  I have a lot of trouble imagining that this moon has literally a planetary-sized ocean (the estimate, if you didn’t read the Wikipedia article, is twice the volume of Earth’s oceans) with absolutely nothing living in it.  Granted that “I have trouble imagining” isn’t the greatest example of scientific reasoning in the history of time, but whatever, my nonexistent reputation as a scientist will survive.

(Also: one of the greatest things about being an amateur astronomer is just how fast the field changes.  When I was a kid, the thought of extraterrestrial planets was considered vaguely ludicrous, as we hadn’t found any yet.  Now that I’m old we’re finding twenty Goldilocks planets a month and there are at least half-a-dozen moons in our solar system alone that we think could potentially harbor or have harbored some sort of life.  The possibility of life outside Earth has gone from a massive improbability to something that seems virtually certain.  All these planets, all these moons, and life nowhere but here?  Bullshit.)

Anyway, here’s the reason I’m even talking about this:  A movie that I’ve been excited about for a while, Europa Report, comes out today, and it’s doing so in an interesting way: it’s in theaters in limited release but you can also stream it through iTunes.  The film’s creators appear to have put a lot of effort into making the film scientifically plausible, at least up to a point, and I’m super excited about watching it– probably not tonight, as I’ve got plans to eat massive amounts of sushi after work and will want to come home and die– but this weekend.

I like living in the future.