The Search for Life on Europa

Orbiting Jupiter discovered long ago by Galileo, is a moon that appears to be covered with massive ice floes, presumably floating on a vast liquid water ocean. Should this be true, if indeed there is liquid water under the ice, then Europa may be pivotal in Earth’s search for extraterrestrial life. Just the hint of it being true is reason enough to explore Jupiter’s third largest satellite.

A Look at Europa

Just slightly smaller than the Earth’s moon, Europa is the sixth largest moon in the solar system and is believed to be a rocky object covered in a layer of liquid water under an outer shell of ice. Europa has its own atmosphere, albeit a very tenuous one, that is primarily oxygen. Boasting one of the smoothest surfaces in the solar system, Europa has intrigued astronomers for centuries, and has already been the target of some exploration in the form of fly-by missions, not yet rating its own mission. With all of the criteria that could suggest potential extraterrestrial life on Europa, however, that may soon change.

Building a Case

There are a number of theories and bits of evidence that all form potential puzzle pieces in the exploration of potential life on Europa. One of the most striking features of the satellite are dark lines that crisscross the surface and are thought to be remnants of a time when warm water burst through the icy crust. Differences in the positioning of icy rafts of the crust suggest they are floating on a liquid surface. Discrepancies in the orbit of Europa are evidence of Jupiter’s effect on the moon’s travels, which could result in tidal action which, in turn, could produce enough of an energy source to keep water liquid. Europa has a weak magnetic field, one which shows spikes in strength when passing through Jupiter’s massive magnetic field. This is strong evidence of a potential salt water ocean beneath the ice. All of this is building a case that Europa does, after all, possess a liquid water ocean, but even if it did not, the permafrost nature of the surface could house the life we seek.

Life on Europa, on Earth

The kind of life that could be found in the ice on Europa may very well be similar to the kind of life we are discovering at home on planet Earth. Over the last few years astrobiologists have been turning to the icy fields of Siberia and the poles to drill and sample the ice in search of life, and have discovered that extreme conditions will not necessarily rule out the potential of life. Moss and lichen frozen for 40,000 years was found alive in Siberia, amazing scientists and opening the door to possibility for extraterrestrial life elsewhere.

Final Thoughts

The Jupiter Icy Moons Orbiter mission was cancelled in 2005, the most ambitions proposal to date. NASA is currently considering future explorations to Europa that would focus on the following goals: 1) Confirm the existence of a subsurface ocean, 2) Image surface features, 3) Examine chemical make up of surface, 4) Use radar to probe for ocean 5) Place a Lander on the surface.