NASA really wants to go to Europa, and anyone who knows anything about exobiology really wants NASA to go to Europa. Why?
On Earth, water is what fuels life. Of course, there are a lot of other things that fuel life on our planet, but water is an integral part of life as we know it. Indeed, so far all of our research has indicated that--where there is water, there is life (Earth isn't called "the Pale Blue Dot" for nothing). And while it is possible that alien life could exists on other worlds and thrive off of something else entirely (iron, maybe?), when one is searching for the first signs of life out in the universe, it makes sense to look for it in familiar places.
Which is precisely why we turn to water.
Really, the universe is kind of a big place, so it wouldn't make too much sense for us to head to the volcanic plains of Venus, even though it is similar in size to Earth, as we've no real indication that life is likely going to be found there (though it is still a possibility). Moreover, water is a logical place to look for life as Earth's oceans are home to a variety of life at every depth (even the darkest corners and deepest pits). In addition to this, the National Oceanic and Atmospheric Administration estimates that nearly half of all life on Earth lives in the ocean.
Imagine what we would miss if we didn't plumb the farthest reaches of our water for life? No giant squid, no angler fish...it would be a sad world indeed.
Thus, the above image ultimately demonstrates why we need to go to Europa. According to the information that was complied by NASA's Galileo satellite, the amount of liquid life (water) sloshing about beneath the surface of this tiny, icy moon is approximately 2—3 times more voluminous than the oceans here on Earth. Keep in mind that Europa is a tad smaller than the Earth, well, quite a bit smaller, actually. However, the amount of water that it contains is not more than twice as much proportionally. Instead, there is 2—3 times more in total volume.
Since this moon has such an abundance of H2O, and since it seems that this water is in a liquid state, and since where we find water we find life, scientists think that Europa has an amazing chance of harboring life.
Also note, Europa has been seen ejecting plumes of water into space, so we know that the water beneath is, in fact, in a liquid state. But of course, it is difficult to know exactly how much of this water is frozen. It is possible that the ice may be hundreds of yards thick. Still, even with all that ice, that would leave a lot of liquid water. We would just need to drill a bit to get to it.
Ultimately, the water on Europa is kept in liquid state because of the immense gravitational forces that it experiences because of its proximity to Jupiter, and also because of the moon's global ocean currents (things that we will need to contend with if/when we ever get there).
Fortunately for us, NASA is planning a trip to Europa. Unfortunately for us, traveling to alien worlds is no easy process. The launch is not anticipated until 2025, and the craft will not arrive until 2030 (and that's assuming that the project gets the go-ahead). And of course, that is also assuming that all goes well. It is entirely possible that there will be a number of setbacks. Yet, it is also possible that there will be great advances in our technology, and we may get there far sooner than anticipated (I am not holding my breath on this one, as the economics of the project is still a serious factor, but it is possible).
So, here's to a hopeful future and continued funds for NASA!
Learn more about the potential mission at the video below.