Comet 67P/Churyumov-Gerasimenko
Mark McCaughrean, the ESA's senior adviser for science and exploration, shared @landru79's GIF and offered up some explanations of what we're seeing. What looks like snow flying around is actually a combination of stars in the distance and dust blowing around the comet's surface.

1.3 Gigastars including proper motion and parallax

The second data set release from Europe’s Gaia mission could provide clues to the galaxy’s past and future

Data on 1 billion stars in our galaxy