NASA captures giant Mars volcano piercing through morning clouds

Arsia Mons, an ancient Martian volcano, was captured before dawn on May 2, 2025, by NASA’s 2001 Mars Odyssey orbiter while the spacecraft was studying the Red Planet’s atmosphere, which appears here as a greenish haze. (Image: NASA/JPL-Caltech/ASU)

For the first time, Mars' gargantuan volcano Arsia Mons has been photographed looming above the clouds — and it's one to treasure.

The scene is familiar-looking — a mountain rising up from dawn fog — but the one here isn't on our planet. Photographed by NASA's 2001 Mars Odyssey orbiter, the volcanic monster Arsia Mons on Mars seems to rise above the pre-dawn clouds in a new high-elevation vista. It was captured on May 2. The photo provides a unique horizon view of the Red Planet, the way that astronauts see Earth from orbit.

A New Perspective on Mars

Odyssey, the longest-operating spacecraft orbiting a planet, captured the photo by turning 90 degrees halfway around the planet. Its onboard instrument, THEMIS (Thermal Emission Imaging System), was designed to study the Martian surface. However, since 2023, scientists have utilised it to image Mars' horizon. From these, scientists gain insight into the planet's upper atmosphere, such as yearly changes in clouds and dust.

This fresh perspective emphasises a particular weather pattern — water ice clouds that form over Tharsis Montes, an ensemble of volcanoes that includes the Arsia Mons. In contrast to the more typical carbon dioxide clouds, these water ice clouds accumulate on early morning dates, particularly when Mars is at aphelion, its most distant point from the Sun. The season is marked by an aphelion cloud belt that runs along the equator of the planet, with Arsia Mons towering underneath.

Arsia Mons: Mars' Colossal Volcano

Standing 20 kilometres high on the Martian surface, Arsia Mons is almost double the height of Mauna Loa, Earth's highest volcano. It's also the cloudiest of Mars' Tharsis volcanoes. As wind ascends the volcano slopes, the air thins and rapidly cools, condensing into thick layers of morning clouds that encircle the summit.

NASA researchers specifically chose Arsia Mons for this new picture, hoping to catch its summit punching above the fog — and they did. Jonathon Hill, operations manager for the THEMIS camera at Arizona State University, explained the outcome wasn't disappointing. It's not just a pretty picture but also contributes scientifically.

Unlocking Clues to Martian Weather

Through this vantage point of the Martian atmosphere, scientists are becoming aware of seasonal changes and weather patterns. NASA's Goddard Space Flight Centre's Michael D. Smith mentioned that the horizon images are showing significant atmospheric changes. This information could assist in aiding future missions, particularly entry and landing phases.

The THEMIS camera has other important advantages as well. It can see in both visible and infrared light across the Martian surface, assisting in the detection of water ice below the surface. That might one day be crucial for future space travellers on the planet. THEMIS also watches over Mars' moons Phobos and Deimos, providing scientists with hints about their surface materials.

A Legacy That Continues to Inspire

Odyssey’s mission is managed by NASA’s Jet Propulsion Laboratory, with spacecraft construction and operations supported by Lockheed Martin Space. THEMIS, designed and operated by Arizona State University, continues to produce insights more than two decades after launch.

With Arsia Mons now seen from a whole new angle, scientists are looking forward to what the Martian horizon will reveal next.