It’s a question that we’ve been asking ourselves for a long time (Pink Floyd’s version notwithstanding). We might be a step closer to finding out the answer.
A new look at data from the Galileo space probe which orbited Jupiter for over a decade has given scientists greater evidence for water plumes coming from Europa, one of Jupiter’s four largest moons. Europa has long been seen as one of the best places to look for life in our solar system (besides the Earth, of course!), and the existence of plumes of water rising up from the surface would make the search a lot easier.
Why Europa? The Jovian moon, which is just slightly smaller than our own lunar neighbor, appears to have even more water on it than our entire planet. It’s far from the Sun, so the surface of Europa is a cracked ice sheet. But under that ice, liquid water appears to reign supreme…and on Earth, where there’s water, there’s life. Is the same true for Europa?
What’s the big deal about the plumes? Well, if we want to see if there is anything swimming around in the Europan ocean, we would need to land on the moon, and try to find a way under that cracked icy surface. That might even involve drilling a hole to get under there. While that’s possible, it makes for a complex spacecraft…and it means we run the risk of disturbing the ecosystem of Europa if one exists. We’d rather not do that, if we can help it. If Europa is ejecting plumes of water out into space from under that crust (perhaps thanks to the equivalent of underwater hot springs) we can send a spacecraft to fly through those plumes and test the water samples for the presence of simple life, or the byproducts of life. No need to land on the surface at all!
Either way, it will still be a while before we send that spacecraft on its way. While NASA has had proposals on the drawing board for a Europa mission for decades, nothing has been funded to completion. Currently, the best hope is the Europa Clipper mission, slated to launch perhaps in the 2020s.
I hope we get moving to Europa soon. It still represents the best possible chance for life in our solar system beyond our Earth. Even if it’s only bacteria, it would still be an incredibly exciting discovery.
I can’t wait to find out what’s under all that ice!