Emily Lakdawalla is the senior editor and planetary evangelist for the Planetary Society. She’s also one of the most knowledgeable people I know about everything that’s going on in the Solar System. From Curiosity’s exploration of Mars to the search for life in the icy outer reaches of the Solar System, Emily can give you the inside scoop.
In this short interview, Emily describes where she thinks we should be looking for life in the Solar System.
My name is Emily Lakdawalla, and I’m senior editor and planetary evangelist for the Planetary Society.
There’s a lot of different places to search for life in the solar system. If you use liquid water as your proxy for places we should search for life, there’s actually liquid water all over the place, because most icy moons of outer planets probably have liquid ocean layers inside them. There might even be some Kuiper belt objects that have liquid oceans – Pluto could have liquid ocean.
However, liquid ocean isn’t quite enough, because you also need active chemistry, and for that you really need for the ocean to be in contact with rock or some material that is not just more ice, because that is where you can get all kinds of chemical elements to build interesting molecules out of.
And so there are a couple of places where we know that’s happening. Europa being the big one, where its a large moon that has a thin ocean that’s likely in direct contact with a warm rocky core, and it’s a world that we know is geologically active, so we know that there’s a source of energy coming up from below. And geologic activity brings up all kinds of chemistry – you might have black smoking vents on the ocean floor of Europa, and we know what kinds of cool stuff we find in those environments on Earth, so it would be really awesome to explore Europa and find the same kind of black smoking vents, and who knows – maybe little microbes swimming around.
Should we be looking in places other than Europa?
Europa’s one of the likeliest places to search for life outside of the Earth. A problem, though, is that it’s ice shell is very thick, so if you want a place where it’s ocean is likely in contact with rock on a geologically active world that is much easier to get to, it’s hard to do much better than Enceladus, which a very small moon of Saturn which has these active geysers spewing from it’s south pole.
Those geysers are salty – it’s a salt water ocean, so we basically have a world that is conveniently venting it’s ocean out into space. You don’t even have to land – you can just fly right through that plume and check to see what kinds of cool chemistry is happening there. So yeah, I think Enceladus would be a really cool place to explore for life.