Europe on the Earth, Europa in Outer Space

Ah, Europa. When we look at our own moon and then take a peak at the fourth largest of Jupiter we see a good number of differences.

Well, ladies and gentlemen, those brown gashes across the icy surface are silicate rock; what the moon is primarily composed of. Why are there no craters? Not only is there ice on this baby, there's water, so there aren't any craters left behind, it gets filled in and re-frozen after any collisions. Neato!

She's got a diameter of 3000 km and is the sixth largest moon in the entire solar system (just beneath ours, of course). Galileo found her in January of 1610

That suspected ocean beneath the ice layer is quite fascinating, I must say. With an energy source of tidal heating, no wonder there's thought of the possibility of life being on this special moon. That heat keeps the water liquid and makes a high possibility of geological activity. Imagine? A world of water beneath that surface of ice and rock? Reminds me of something we'd see in Star Trek and it's in our own solar system.

I was surprised to find out that Europa's name wasn't used for a period of time after it's designation and was instead called Jupiter II. How boring. I know I wouldn't like it if I was called Hollett IV just because my parents didn't feel like calling me by my name for a couple of years. Terrible. Too much wine, probably. Thankfully, in the 20th century, they put the bottles back in the cellar and decided to call her (and a few other Galilean satellites) by her proper name. She was called Jupiter II because she was the second satellite to be found orbiting Jupiter. Later on, four more were found and were actually closer to the massive gas giant, and she was then demoted to sixth position. But she's still called Jupiter II. They took away her name but won't change it to make it appropriate again. *Sigh*

As one of the smoothest objects in the solar system, Europa's albedo (light reflectivity) is one of the highest for satellites at 0.64 due to it's icy surface. That's pretty darn bright; no wonder we can see it from Earth on a good clear night.