Life on Titan?
Places to look for life in our Solar System
Places in the Solar System where life might exist (except the Moon and Ceres, which are just shown for scale).
Credit: D. W. Hoard (2018), assembled form public domain NASA imagesSaturn's largest moon, Titan, is the only moon in our Solar System with a substantial atmosphere, and the only Solar System object (other than Earth) known to have stable reservoirs of surface liquids.
This colorized mosaic of radar images from NASA's Cassini mission shows the most complete view yet of Titan's north pole region, an area of lakes and seas. Detailed analysis of the radar data revealed that these oceans have waves, but the waves are typically only about 1 cm high.
The liquid in Titan's lakes and seas is mostly methane and ethane. Almost all (97%) of Titan's surface liquids are found in the region shown here. In this color scheme, liquids appear blue and black depending on the way the radar bounced off the surface. Land areas appear yellow to white.
Credit: NASA/JPL-Caltech/ASI/USGS [link]
Satellite image of the Great Lakes on Earth, shown at the same size scale as the image of Titan's liquid hydrocarbon oceans.
Credit: SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE; cropped and labeled by Beyond My Ken (Wikimedia Commons) [link]Life on Titan?
Not as impossible as it sounds!
Make the following substitutions:
Liquid methane/ethane for water
Liquid water for lava (molten rock)
Water ice for rocks
Then Titan’s surface features and geologic processes are remarkably similar to those of Earth!
Reminder: here (in really simple terms!) is how human metabolism works...
Glucose (C6H12O6) & oxygen are turned into carbon dioxide & water
Is it possible for life to evolve based on liquid hydrocarbons instead of water?
YES!
Methanogens exist on Earth.
These are microorganisms that produce methane as a metabolic byproduct in anoxic (no oxygen) conditions.
Carbon dioxide & hydrogen are turned into methane (CH4) & water
Some methanogens live in the digestive tracts of cows and humans!
Where does the methane go? (think about it…)
On Titan, the metabolism of life might use:
Acetylene (C2H2) & hydrogen are turned into methane (CH4)
This is a contrast-enhanced version of the image was obtained in 2005 by the Huygens probe from the surface of Titan.
The two rock-like objects (rock or water ice) just below the middle of the image are about 15 centimeters (about 6 inches) [left] and 4 centimeters (about 1.5 inches) [center] across respectively, at a distance of about 85 centimeters (about 33 inches) from Huygens.
The surface is darker than originally expected, consisting of a mixture of water and hydrocarbon ice. There is also evidence of erosion at the base of these objects, indicating possible flowing liquids (most likely liquid hydrocarbons like methane or ethane).
Credit (image and some text): ESA/NASA/JPL/University of Arizona; processed by Andrey Pivovarov [link]