Water on Mars? That's an ongoing question, but there's definitely a crater filled with ice year-round, Science Alert reports. New images from the European Space Agency's Mars Express show the Korolev crater, which measures 50.6 miles in diameter and 1.2 miles deep, filled nearly to the brim with ice. The European Space Agency calls the "winter wonderland" a "cold trap" because the crater's deepest parts—further down than the Grand Canyon's, per Space.com—trap air blowing along the planet's surface. The sunken air cools, producing a cold layer that insulates ice and keeps it from melting.
Named after Soviet rocket engineer and spacecraft designer Sergei Korolev, the crater was no doubt forged by a huge impact somewhere in the planet's past. The latest images were composited from five pics snapped by the Mars Express, an orbiter that's given us detailed photos of the planet's surface and possible signs of liquid water since launching in 2003, per Engadget. The orbiter is now accompanied by NASA's Insight lander, which arrived in November to "screams, applause, and laughter." (Here's what wind on Mars sounds like.)