As Earth’s northern hemisphere enters winter, Mars’ north pole is experiencing a dramatic spring thaw, featuring frost avalanches, explosive gas geysers, and massive shifting dunes that reveal the Red Planet’s active seasonal transformation.
Published in NASA/JPL News | Estimated reading time: 4 minutes
“Springtime on Earth has lots of trickling as water ice gradually melts. But on Mars, everything happens with a bang,” explains Serina Diniega, who studies planetary surfaces at NASA’s Jet Propulsion Laboratory in Southern California. Unlike Earth’s gentle thaw, Mars puts on a more explosive show as its ice transitions directly from solid to gas in the planet’s thin atmosphere.
The Martian year, which spans 687 Earth days, concluded on November 12, 2024, initiating spring in the planet’s northern hemisphere. Using cameras and sensors aboard the Mars Reconnaissance Orbiter (MRO), scientists are tracking remarkable seasonal changes that shape the planet’s surface.
“You get lots of cracks and explosions instead of melting,” Diniega said. “I imagine it gets really noisy.” In 2015, MRO’s cameras caught a spectacular glimpse of this violent thaw – a 66-foot-wide chunk of carbon dioxide frost in mid-avalanche.
Perhaps most striking are the planet’s gas geysers, which erupt when sunlight penetrates carbon dioxide ice, turning its bottom layers directly into gas. The pressure builds until it explodes upward, scattering dark fans of sand and dust across the surface. In some areas, these explosions leave behind distinctive patterns that researchers call “spiders” – long scour marks that resemble arachnid legs when viewed from orbit.
At the north pole, powerful spring winds carve massive troughs into a Texas-sized ice cap, creating swirling patterns visible from space. “These things are enormous,” notes Isaac Smith of Toronto’s York University. “You can find similar troughs in Antarctica but nothing at this scale.” Some of these features stretch the length of California, channeling warm winds that help reshape nearby sand dunes.
Each northern spring varies slightly in intensity, affecting how quickly ice sublimates and controlling the pace of these surface phenomena. Scientists continue monitoring these changes through MRO’s cameras, which have provided nearly two decades of observations, helping decode Mars’ dramatic seasonal transformations.
Glossary:
- Sublimation: The process of a solid transforming directly into gas without becoming liquid first
- Carbon Dioxide Ice (Dry Ice): Frozen carbon dioxide that is more abundant on Mars than water ice
- Adiabatic Process: A natural warming effect that occurs when winds flow down slopes, gaining speed and temperature
Test Your Knowledge
How long is a Martian year?
687 Earth days
What happens to ice on Mars during spring thaw?
Instead of melting into liquid, it sublimates directly from solid ice into gas
What creates the spider-like patterns on Mars’ surface?
Scour marks left behind after gas geysers erupt through carbon dioxide ice, leaving long channels in the surface
How do the north polar troughs affect Martian wind patterns?
The troughs act as channels for spring winds, causing them to increase in both speed and temperature through an adiabatic process as they flow downslope
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