Are you dreaming of a White Christmas? Have you ever wondered if it ever snows in space? Well, sometimes, yes! 

Mars has been known to have small snow flurries, made of the same frozen carbon dioxide we call dry ice. While you may have seen “snow” from NASA’s Solar and Heliospheric Observatory (SOHO) back in 2015, what you were actually seeing was a solar radiation storm! While these bursts of incredibly fast-moving protons and electrons are fairly common, the storm that triggered the “snow” that you could see from SOHO was unique: a low-level solar flare and two relatively slow coronal mass ejections (large expulsions of plasma and magnetic field from the Sun’s outermost atmosphere), rather than the strong, fast eruptions that normally produce them.