A rare meteoroid impact on Mars has given scientists a glimpse into how the planet’s dusty surface is constantly reshaped.
When a space rock struck near the edge of Apollinaris Mons, a large volcano on Mars, it caused a chain reaction that sent fine layers of dust sliding down nearby slopes.
The result: more than a hundred fresh streaks etched into the red planet’s surface.
The discovery was made by the European Space Agency’s ExoMars Trace Gas Orbiter, which spotted the scene the night before Christmas in 2023.
Its onboard Color and Stereo Surface Imaging System (CaSSIS) captured clear images of the impact site, showing a faint cluster of small craters surrounded by a lighter, disturbed area at the base of the slope.
By comparing these new pictures with older images, scientists determined that the impact and dust avalanches occurred sometime between 2013 and 2017.
On Mars, these dark streaks are common sights on steep hills and crater walls. They form when the thin layer of reddish dust that coats the surface suddenly slides downhill, revealing a darker layer underneath.
While these features might look like they’re caused by flowing water, scientists say they are actually created by dry processes.
Mars’s thin atmosphere and cold climate make it nearly impossible for liquid water to exist on the surface today.
A new study published in Nature Communications reveals that such meteoroid-triggered streaks are exceptionally rare — fewer than one in a thousand streaks form this way. Most streaks appear as a result of wind and seasonal dust movement.
“Dust, wind, and sand dynamics appear to be the main seasonal drivers of slope streak formation,” explains lead author Valentin Bickel from the University of Bern in Switzerland.
“Meteoroid impacts and quakes seem to be locally distinct, yet globally relatively insignificant drivers.”
To reach this conclusion, Bickel and his team used artificial intelligence to analyze more than two million slope streaks captured by NASA’s Mars Reconnaissance Orbiter between 2006 and 2024.
The AI tool helped map out where these streaks form most often, identifying five main hotspot regions across the planet.
“These observations could lead to a better understanding of what’s happening on Mars today,” said Colin Wilson, ESA’s project scientist for the ExoMars Trace Gas Orbiter.
The orbiter continues to capture stunning images and collect data on Mars’s surface and atmosphere, helping scientists learn more about the planet’s history — and whether it was ever capable of supporting life.
