When you think about massive, mysterious cosmic bodies like accretion disks, the water swirling around your bathtub probably isn't the first thing to come to mind. But hey, physics works the same magic on all scales.
These days, we may take the stars for granted, but it's not hard to imagine the wonder early humans must have felt gazing up at those inexplicable points of light. Naturally, superstitions were bound to develop — some more fortuitous than others.
When a huge star collapses, it releases massive amounts of radiation in concentrated streams. If one of those streams hit Earth, it wouldn't be pretty. But where should we put "gamma-ray bursts" on our list of anxieties?
Precipitation does fall from the clouds of other planets, but it's a little more exotic than the good, old-fashioned rainwater we get here on Earth. Imagine sheets of methane, sulfuric acid and, yes, even diamonds falling from the sky.