Earth seems like the exemplar for nurturing life. It has huge oceans, close enough proximity to the sun to keep those oceans from freezing, a hospitable atmosphere and our huge population proves its success. As a result, many people believe that life may thrive on planets just like ours. Further, NASA scientists expect to discover alien life within the next twenty years in a region that appears inhospitable: the icy moons of Jupiter.
Jupiter has four large moons: Io, Europa, Ganymede, and Callisto. Scientists believe that there could be water on all four moons, and in March 2015 they used the Hubble Telescope to confirm that Ganymede has signs of flooding on its surface. Even with this exciting new information, Europa is currently the hot topic among astrobiologists.
Due to the geysers on Europa’s surface and the interruptions it causes in Jupiter’s magnetic field, scientists believe that there is an entire ocean beneath the moon’s crust. It’s widely believed that the essential ingredient for life is liquid water, and it turns out that Europa may generate enough heat to keep its ocean from freezing. Europa travels around Jupiter in an elliptical orbit, meaning that its distance from the planet varies over time. As the moon moves around the planet, the forces Jupiter exerts fluctuate. The friction and change in shape due to varying forces releases a lot of energy and, just as a paperclip might get warm as you bend it back and forth, Europa starts to heat up. This motion, combined with suspected volcanic activity and heat radiating from the core, makes Europa a lot warmer than its icy crust might suggest. All this heat could keep the ocean from freezing, creating an inviting habitat for microorganisms.
Basically, with water comes life, and with life comes a band of eager NASA employees waiting for mission approval.
Luckily, this approval has come, thanks to the increase in the 2016 NASA budget. The mission concept, called the Europa Clipper, will dive through Jupiter’s radiation belt to fly over Europa’s surface 45 times over the course of its three-year mission. These passes could allow scientists to study Europa’s atmosphere and environment, and possibly even collect samples of the seawater. These samples and others could provide valuable information as to the status of life on the moons of Jupiter.
The discovery of life outside Earth would present an ethical question: how much should humans interfere? If a meteor is heading towards a planet with life, should we try to deflect it? Should we try to cultivate this life to encourage it to flourish? Since the organisms developing would be small and insignificant in many contexts, some individuals would see no problem with colonization or invasive research. Overall, we need to determine policies for dealing responsibly with extraterrestrial life.