Is there life on Saturn's moon Enceladus?

Saturn’s tiny moon Enceladus may offer the next best hope for finding life elsewhere in our solar system, astrobiologists now say. An article published in Forbes April 29 by Bruce Dorminey, titled “NASA May Plumb For Signs Of Life In Enceladus' Plumes,” discusses two potential mission proposals to Enceladus to sample its towering geyser-like plumes of water erupting from its frozen surface.

Both proposed NASA missions involve ASU researchers.

The Cassini spacecraft discovered an icy plume erupting from an ancient salty ocean inside Saturn’s moon Enceladus and proved it contains organic molecules. These factors, added with the icy satellites geothermal energy, make plausible the idea that life exists on this tiny moon.

The first proposed mission, called ELF (short for Enceladus Life Finder), would follow in Cassini’s footsteps, using two state-of-the-art instruments to measure the ocean’s history, habitability and biotic state.

ASU professors Ariel Anbar and Everett Shock make up the ASU portion of the multi-institutional team that designed the proposal.

“If you really want to look some place in the solar system and determine whether life could independently arise on any body, then Enceladus is a great bet,” Anbar is quoted as saying in the Forbes article.

While giant geysers erupting over an icy surface sound fascinating, astrobiologists aren’t expecting to find life there. It’s the warmer, liquid waters beneath the surface that interests them.

The article quotes Anbar as saying, “It’s not likely that anything is living in the plumes because the particles freeze pretty fast when exposed to space. But there could be things living in the oceans that the plumes are sampling.”

The proposed ELF mission would make use of today’s capabilities, including mass spectrometers of much higher resolution and range, and that would measure key chemical indicators of just how habitable Enceladus’ ocean is, such as temperature, pH and oxidation state.

Of course, the only way to tell if life exists in Enceladus’ subsurface ocean is to collect ocean water samples – which is what the second proposed mission, dubbed LIFE (short for Life Investigations For Enceladus), seeks to do.