- Ganymede is oddly large for a moon. It’s much larger than Earth’s moon. In fact, it’s larger (in terms of radius) than the planet Mercury, and it’s almost as large as Mars.
- Ganymede has it’s own magnetic field, providing some protection from solar and cosmic radiation. No other moon can claim that.
- Ganymede has a thin oxygen atmosphere. It’s nowhere near an Earth-like atmosphere, so leave your space helmet on. But still… oxygen!
All this, combined with plentiful liquid water beneath Ganymede’s surface, would make you think Ganymede is ripe for human colonization.
And indeed, Ganymede has been portrayed multiple times in science fiction as a major human outpost in the outer Solar System. But before you pack your bags and slap a “Ganymede or bust” sign on your spaceship, a note of caution.
Ganymede orbits within Jupiter’s radiation belts. While Ganymede’s magnetic field would provide some protection, it’s not enough to protect you from the radiation concentrated in those radiation belts.
Of course in a distant Sci-Fi future where humanity has overcome the radiation dangers associated with Lunar or Martian colonization, the colonization of Ganymede will seem much more plausible. In the meantime, NASA has its sights set on a different target for human space exploration.
Next week, we’ll be meeting (and possibly colonizing) a moon named Callisto.