NASA Astrobiology - 17 June 2010
Astrobiology Magazine | 17 June 2010Jupiter’s moon Europa has a salty ocean where life could exist, but in order to explore it, we need to drill through the moon’s thick ice shell. However, some scientists believe that the remains of marine life on Europa could be accessible on the surface for a lander to find. The icy surface of Europa is covered in cracks and fissures, and it might be possible that organisms are dragged to the surface as these features form. Experiments performed at NASA’s Jet Propulsion Labs even suggest that orbiters could investigate the infrared signature of Europa’s icy crust to look for tattered remnants of life.
[/list]If extraterrestrial life exists on Jupiter's moon Europa, instead of deploying probes to drill past its ice shell to look for aliens in the ocean below, one might just go fossil-hunting on the icy surface.
Europa, which is roughly the size of Earth's moon, is enveloped by a global ocean that may be about 100 miles deep (160 km). This ocean is overlain by an icy crust of unknown thickness, although some estimates are that it could be only a few miles thick. Since wherever there is water on Earth there is a chance of life, for many years scientists have entertained the notion that this Jovian moon could support extraterrestrials. Recent findings even suggest its ocean could be loaded with oxygen, enough to support millions of tons worth of marine life like the type that exists on Earth.
To see if any kind of life actually evolved on Europa, scientists have proposed missions to drill through its outer shell, perhaps using heat to melt through the ice, whirring blades to clear away rocks and robot subs to explore the ocean.
However, rather than deploying complex equipment to try and penetrate an uncertain distance into the ice, the remains of marine life on Europa could be available right on the outer shell for landers to find. Scientists aren't suggesting that any life from Europa somehow managed to dig its way up through the ice. Instead, the constant upheaval this Jovian moon undergoes could drag unwitting organisms upward.