It’s the return of that ‘life moving between planets’ meme, only this time with a twist. Instead of being liberated by asteroid collisions with life-bearing planets, what if microbes got caught up in the planet’s magnetic field, and ended up riding the flux lines out beyond the atmosphere, all the while sustaining no damage from heavy collisions and evolving the ability to survive in hard vacuum and high-radiation situations? The mind boggles…and a thousand science fiction authors run for their notebooks.