Have you wondered where some form of life might exist within our own solar system?
Over the past year or two the case for Jupiter’s moon, Ganymede, has kept getting better. Let’s start with basics: Ganymede is larger than both Mercury and Pluto, and is 2/3 the size of Mars with a diameter of 5,268 km or 3,273 miles–8% larger than Mercury. It has the highest mass of all planetary moons and has more than twice the mass of Earth’s Moon. Gravity is about 15% of Earth’s; it has huge subsurface (salty) oceans, a magnetic field and aurora—yes, like our Northern Lights. Ganymede has a core of metallic iron, followed by at least one layer of rock, the subsurface oceans topped off by a thick crust of mostly ice. There is almost no atmosphere, and what traces exist appear to be ozone! Any life on the surface would have to be able to exist in deep cold with no air to breathe, and some electrically-charged oxygen molecules (ozone) floating just over the surface. But we all know life can exist in oceans, even without much light…so?
It was the shift in Ganymede’s aurora which helped to prove the salt water oceans part this year: https://www.sciencenews.org/article/aurora-shift-confirms-ganymede%E2%80%99s-ocean
The salt water part is the neatest—I wondered how the heck all that water got on Ganymede, and where did the salt come from? The oceans may very well be in layers, one ocean on top of another, separated by rock and ice. Yes, a subsurface club sandwich of oceans! In short, a science fiction writer’s dream world, not that far away, and very real. Would I like to write a science fiction story about intelligent life in the oceans of Ganymede? No comment!
Finally, check this out: http://www.jpl.nasa.gov/news/news.php?release=2014-138