Aug 8, 2011
Earth's (Invisible) Ring
Yes, along with the cloud of positrons that's floating above the atmosphere, Earth also has an invisible ring of anti-protons hovering in the Van Allen radiation belt. Anti-protons are, shockingly enough, the anti-matter counterpart to protons, just as positrons are the ying to the electron's yang. New Scientist has the story, in which they posit that this newfound collection of naturally occurring anti-matter could be used to fuel future generations of spacecraft.
So it looks like someone finally made an honest woman out the planet. My money's on Mercury. He's such a smooth talker...