Over the last few decades our knowledge about some of the many Moons in our solar system has changed. It has been discovered that for a world to have stable conditions for life, it is not required to be in the Goldilocks zone. Moons orbiting super planets can also meet the conditions which would allow life to evolve. Better still, several of the moons in our own solar system meet these conditions. Following is a little guide to six Moons in our solar system which are gaining special attention, and over the next few years will almost certainly transform Exobiology from theoretical science into practical science.
Ganymede, this moon of Jupiter is the largest moon in the Solar System, indeed it is larger than the planet Mercury. Ganymede is believed to have an oxygen atmosphere and uniquely, from all the other moons in the solar system, a magnetosphere. Most interestingly perhaps, Ganymede is believed to have a large saltwater ocean with a rocky sea floor.
The above artist impression shows why Ganymede is so interesting.
Europa. A moon of Jupiter, slightly smaller than our own moon. Like Ganymede, Europa has an oxygen atmosphere and a vast saltwater ocean.Europa is a very stable moon and life on it, if any, could have had a long time to evolve and ecosystems formed. This could allow for ‘larger’, more sentient creatures to evolve. For this reason we must be careful not to contaminate Europa.
This artist impression again shows why Europa is so interesting.
Callisto. Moon of Jupiter. Again this moon is believed to have a subsurface liquid water ocean. Of future interest for Jupiter watchers, Callisto is being eyed up as a potential base camp location for any manned missions to the Jovian system.
Above is the suspected internal structure of Callisto.
TITAN. Oh Titan Saturn’s largest moon. Like its name suggests, this is a large moon, indeed the second largest in the solar system and like Ganymede, larger than the planet Mercury. Titan is extremely interesting, those glints in the northern section of the above photograph actually show infrared sunlight reflecting off vast Hydrocarbon seas on Titan surface. The Northern portion of Titan has large liquid lakes and seas with coastlines and islands. Titan also has a dense, Nitrogen rich fully evolved atmosphere, with Troposphere, Stratosphere, Mesosphere & Thermosphere. Titan has weather, with methane rain and snow falling onto its surface. On that surface, as stated are lakes and seas, but also valleys, mountains, hills, deserts, river systems and you maybe suprised to hear, a ESA /NASA probe landed on it’s surface in 2005. Huygens probe.
Below Titans surface its believed liquid ammonia/water oceans 200km deep could exist. Indeed Titan is an amazing world.
above is Titans suspected internal structure.
Enceladus is a moon of Saturn and whilst small (it could fit in the North Sea between Great Britain and Holland), its very interesting. It southern region is of most interest with Cyrovolcanoes (ice volcanoes) and over 100 Geysers. It is highly likely a liquid water ocean is under the ice to its south. It is believed hydro-thermal activity occurs within its Ocean. Organic chemistry has been detected in the southern active plumes/jets.
An artist impression of the suspected internal structure on Enceladus.
DIONE, another moon of Saturn. Dione is mostly made up of water ice. It has a very thin Oxygen atmosphere and recent findings suggest it may have a subsurface Liquid water ocean.
further study ~