Phil Plait's Bad Astronomy website started out mainly as a forum for nitpicking the science in movies (hence the name) but over the years, Phil has turned it into a valuable and entertaining way of educating people about astronomy. Here's a video of Phil answering an intriguing question, "why don't giant clouds of gas dissipate in space?"
Mt. Etna Lava Plume - [image: Mt. Etna Lava Plume] Mt. Etna Lava Plume
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