Of anti-protons! While it's not as visually cool as what Saturn has going for it, this is still an important development, even if we can't technically "see" the ring with our primitive Earthling eyes.
According to New Scientist, this anti-proton ring joins the previously discovered positron cloud that's also circling the Earth like an invisible shield. Ironically, the anti-protons are 2,000 times more massive than their positron counterparts, but were discovered second. Both are trapped in a donut-like ring called the Van Allen radiation belt that's held in place by the planet's magnetic field.
In the distant future, a spacecraft designed to use anti-protons (or other types of antimatter) as a fuel source could tap into this ring to top off its tanks and head out into the void, said Alessandro Bruno, a member of the University of Rome Tor Vergata team that confirmed the anti-proton area's existence. I'm really looking forward to that not happening in my lifetime! [New Scientist, Image]