The latest images of Enceladus (pronounced en-SELL-la-duss) sent by the Cassini space probe are nothing short of amazing. Enceladus is Saturn’s sixth largest moon, measuring only about 500km in diameter. The moon is cold, very cold. It’s temperature reaches -198 Celsius. It is also covered in ice. What’s interesting when you look at the picture above is that there aren’t a lot of craters and there are cracks, hills and valleys. Normally a relatively static moon like our own would be covered in craters because there is nothing to erode the ridges or fill in the dips. Why not on Enceladus? Evidently a number of water geysers at one of the moon’s poles spray water (that turns to ice) high above the surface. This ice falls back on the surface like snow. Also, gravitational forces from Saturn and other moons constantly pull at the diminutive celestial body, moving the ice around and causing the equivalent of geologic features.
Why is this important and what does it have to do with aliens?
First off, if there are water geysers then by definition there is water, liquid water, on Enceladus. Because there is liquid water, there must also be a heat source. Remember that at noon on a “summer” day, Enceladus reaches a balmy -198 degrees C. Without a heat source, there could be no liquid water. The small moon would be frozen solid. So something is heating the water to above freezing. Life, at least life as we know it, needs water, essential chemicals and an energy source to survive. We know for a fact that Enceladus has water. We also know that something is heating the water. That’s two of the three. It’s not too much of a stretch to think that necessary chemicals are there too.
So could alien life be as close as Saturn? I think the answer is yes. As a matter of fact, I’d bet on it and it might be closer still. In 2012, the Hubble Space Telescope took pictures of water plumes on Jupiter’s moon of Europa. Like Enceladus, it has an icy crust with an ocean of water underneath. There is such interest in Europa as a possible site to find extraterrestrial life, that a NASA is going to send a spacecraft there to investigate sometime in the mid-20s. Everywhere on Earth where liquid water is found, life is present. Is that same thing true on other worlds? We’ll find out in about 10 years.