Plate Nº 88 · recorded October 10, 2026
Space & AstronomyReported finding
Mars's Oddest Cloud May Be Even Odder Than We Thought
Scientists using ESA's Mars Express and a Mars weather model say exotic physics may drive the planet's most curious cloud, a long formation near Arsia Mons.
By Nathan Brooks3 min read597 words
In brief
- Scientists used ESA's Mars Express orbiter combined with a state-of-the-art Martian meteorological model for the finding.
- The study concerns the Arsia Mons Elongated Cloud, Mars's most curious cloud formation.
- The researchers concluded there may be 'very exotic physics' behind the cloud's formation.
- The result is hedged as preliminary — the exotic-physics explanation 'may' hold rather than being confirmed.
A cloud that stretches hundreds of kilometers from the flank of a Martian volcano may be powered by physics unlike anything scientists expected on Mars, according to new research relying on the European Space Agency's Mars Express orbiter.
The finding, reported by scientists working with data from the long-running spacecraft, points to what the researchers describe as "very exotic physics" behind Mars's most curious cloud — an unusually elongated formation that has puzzled observers since its discovery.
The team combined observations from Mars Express with a state-of-the-art meteorological model of the Red Planet to reach that conclusion. By pairing real spacecraft data with detailed simulations of Martian weather, the researchers could test how the atmosphere behaves around the cloud's home region in ways that observations alone cannot.
What cloud is at the center of the story?
The formation in question is the Arsia Mons Elongated Cloud, a streak of ice and dust-like particles that appears near Arsia Mons, one of the giant volcanoes of the Tharsis region. Mars Express has photographed it repeatedly, and the images show a long, tail-like cloud spilling away from the mountain's slopes.
Its unusual shape and persistence set it apart from other clouds in the Martian sky, which is precisely why researchers have devoted sustained attention to it.
How did the researchers reach the new conclusion?
The study's approach rested on two pillars:
- Spacecraft observations from Mars Express, ESA's orbiter that has circled the Red Planet since it entered Martian orbit, providing a long record of the cloud's appearance and behavior.
- A state-of-the-art meteorological model of Mars, which simulates the planet's atmosphere and allowed the team to probe the processes that could produce such a cloud.
By checking the model against what the spacecraft actually saw, the scientists could evaluate whether ordinary atmospheric processes suffice to explain the cloud — or whether something stranger is at work.
Their verdict: ordinary explanations may fall short. The researchers concluded that there may be some very exotic physics behind the formation.
How confident should readers be?
The wording matters here. The scientists say the exotic physics explanation "may" hold — a hedge that signals the result is preliminary rather than settled fact.
That caution is standard for this kind of study. Martian meteorology is difficult to observe directly, and even the best models of the Red Planet's atmosphere remain approximations of a system humans have never sampled with the density of instruments available on Earth.
Until the proposed mechanism is tested against further observations, the exotic-physics interpretation should be treated as a compelling hypothesis, not a confirmed explanation.
Why does one cloud matter?
Mars's atmosphere is thin, cold and poorly understood in detail. Any cloud that defies conventional explanation is a clue that some process in that atmosphere behaves in ways researchers did not anticipate.
If exotic physics truly drives the Arsia Mons Elongated Cloud, then textbooks on Martian weather may need revising. At minimum, the finding shows that combining spacecraft data with modern atmospheric models can surface surprises on a planet humanity has studied for decades.
Mars Express, operated by the European Space Agency, has been a workhorse of Mars science, and this result demonstrates that even a veteran orbiter can still contribute to discoveries that complicate what scientists thought they knew.
The researchers' next steps will likely involve testing the model's predictions against additional observations. For now, the oddest cloud on Mars has earned a new distinction: it may be even odder than anyone realized.
via nature.com (Original)