Outside of earth Europa is probably the best place for life as we know it to develop. Beneath the radiation soaked exterior, which consists of an ice layer that could be up to 20KM thick, lies a vast ocean that stretches deep into Europa’s interior. This internal ocean, though bereft of any light, could very well harbor the right conditions to support the development of complex life. However if we’re ever going to entertain the idea of exploring the depths of that vast and dark place we’ll first need a lot more data on Europa itself. Last week NASA has greenlit the Europa Clipper mission which will do just that, slated for some time in the 2020 decade.
Exploration of Europa has been relatively sparse, with the most recent mission being the New Horizons probe which imaged Europa on its Jupiter flyby on its path to Pluto. Indeed the majority of missions that have imaged Europa have been flybys with the only long duration mission being the Galileo probe that was in orbit around Jupiter for 8 years which included numerous flybys of Europa. The Europa Clipper mission would be quite similar in nature with the craft conducting multiple flybys rather than staying in orbit. The mission would include the multiple year journey to our jovian brother and no less than 45 flybys of Europa once it arrived.
It might seem odd that an observation mission would opt to do numerous flybys rather than a continuous orbit however there are multiple reasons for this. For starters Jupiter has a powerful radiation belt that stretches some 700,000KM out from the planet, enveloping Europa. This means that any craft that dares enter Jupiter’s orbit its lifetime is usually somewhat limited and should NASA have opted for an orbital mission rather than a flyby one the craft’s expected lifetime wouldn’t be much more than a month or so. Strictly speaking this might not be too much of an issue as you can make a lot of observations in a month however the real challenge comes from getting that data back down to Earth.
Deep space robotic probes are often capable of capturing a lot more information than they’re able to send back in real time, leading to them storing a lot of information locally and transmitting it back over a longer period of time. If the Europa clipper was orbital this would mean it would only have 30 days with which to send back information, not nearly enough for the volumes of data that modern probes can generate. The flybys though give the probe more than enough time to dump all of its data back down to Earth whilst it’s coasting outside of Jupiter’s harsh radiation belts, ensuring that all data gathered is returned safely.
Hopefully the data that this craft brings back will pave the way for a potential mission to the surface sometime in the future. Europa has so much potential for harboring life that we simply must investigate it and the data gleaned from the Europa Clipper mission will provide the basis for a future landing mission. Of course such a mission is likely decades away however I, and many others, believe that a mission to poke beneath the surface of Europa is the best chance we have of finding alien life. Even if we don’t that will provide valuable insight into the conditions for forming life and will help point our future searches.