Star Walk 2 — Best Astronomy App 💫 on Instagram: "These breathtaking images of Comet 67P Churyumov-Gerasimenko, captured by the ESA’s Rosetta spacecraft in 2016, show what looks like snow — but it’s much more than that. ❄️ Some of the bright specks ARE snow – they are dust and ice particles floating above the comet’s surface. However, much of the apparent "snow" is made of cosmic rays – charged particles zipping through the universe. And if you look closely, many of the specks are actually back