When I first looked at these photos, I thought they were from New Horizons, which famously photographed Tvashtar erupting when it passed by Jupiter in 2007. But nope! It's Cassini! I had no idea Cassini had seen such dramatic plumes from Io. That's what you get when amateurs dig into archival data!

One note about these images: they're taken through an ultraviolet filter. Io looks quite different in an ultraviolet filter than it does in a clear (broadband) filter. Here, for fun, is a New Horizons clear-filter image, which I've animated to show you what happens when you adjust the contrast -- you can reveal hidden plumes!