This is very cool and very beautiful.
It’s a series of time lapse images from the Hubble Space Telescope showing a “light echo” expanding through an otherwise invisible dust cloud. It’s the kind of thing you only expect to see in the movies, but these are real images. The universe seems very static sometimes, moving on geological timescales, but this is very different.
There’s a much bigger image or even better, a time lapse movie (2.14 MB Quicktime) plus others.
I first saw this a while ago, and it stayed with me. Simply awe inspiring.