Slashdot featured this UPI news story about recent Europa discoveries made by the Cassini probe is both interesting and puzzling at the same time.

In summary: the Cassini probe discovered a torus of heavily ionized gas in the same orbit as Europa, which is assumed to be the remains of water molecules which were ripped apart by the bombardment of ion radiation on the surface from Jupiter.

The interesting part is it shows just how nasty the environs around our solar system's largest planet can be. Radiation so strong it can interact with solid matter on that scale is pretty darned impressive (as far as I understand it, which isn't very).

The puzzling part is how this might dim "Europa life prospects". The article simply doesn't address why this is the case, leading me to believe they're probably just parroting a press release that includes this one line without explanation. As I understand it, water, especially a *lot* of water, is actually a pretty darned good radiation shield. This is why radioactive wastes are always kept at the bottom of really deep pools (I once saw a film of them moving some of those piles around... you could see a weird blue glow around the spent rods).

Still, very interesting. Cassini's still on its way to Saturn. Can't wait to see what the little Huygens probe tells us about Titan.