Mars’ northern hemisphere is experiencing an active and explosive spring thaw, with temperatures rising and ice thinning at a much faster rate than on Earth. Unlike the gradual melting of ice on our planet, Martian ice sublimates directly into a gas, leading to violent changes as water ice and carbon dioxide ice weaken and break.
According to NASA scientist Serina Diniega, who studies planetary surfaces at the Jet Propulsion Laboratory, Mars’ atmosphere doesn’t allow liquids to pool on the surface, making the thawing process much more dramatic. “You get lots of cracks and explosions instead of melting,” she said. “I imagine it gets really noisy.”
Researchers are using cameras and sensors aboard NASA’s Mars Reconnaissance Orbiter to study these phenomena and improve their understanding of the forces shaping the dynamic Martian surface. They’ve captured images of frost avalanches, gas geysers, and spiders – the remnants of ice that sublimates into dust.
One of the most fascinating subjects in springtime is the massive ice cap at Mars’ north pole, which is carved into swirling troughs by powerful winds. The troughs act as channels for wind gusts that become more powerful as the ice thaws, creating an adiabatic process.
The winds also reshape Mars’ sand dunes, causing them to migrate over time. Each northern spring brings new variations in the thawing process, leading to unique surface changes on the Red Planet.
As the southern hemisphere starts its spring season in December 2025, researchers will have a chance to observe more dramatic examples of these phenomena, including bigger gas geysers and clearer signs of spider-like scour marks.
Source: https://www.nasa.gov/missions/mars-reconnaissance-orbiter