One of NASA’s Key Cameras Orbiting Mars Takes 100,000th Image

December 16, 2025

3 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

An overhead color view of the Martian surface shows rough and varied terrain in shades ranging from golden tan to electric blue. At upper left, the ground appears more flat and cratered than other areas of the image, and is colored dark grayish-blue with highlights of silver and tan. The upper right corner of the image looks like wavy sand dunes, in shades of dark blue with bright silvery highlights, except for one apparent ridgeline that stands out as an elongated S-shape in electric blue. The bottom half of the image shows more mountainous terrain that gets lighter and more gold-colored nearer the bottom of the frame. A pair of smooth valleys run diagonally between the peaks, from around the center of the image toward the bottom-left corner; the upper one is a shade of silvery blue and the bottom one is a grayish-gold, and both have ridges lining their upper walls, looking like lines of sharp teeth biting into the valleys.

This view of a region called Syrtis Major is from the 100,000th image captured by NASA’s Mars Reconnaissance Orbiter using its HiRISE camera. Over nearly 20 years, HiRISE has helped scientists understand how the Red Planet’s surface is constantly changing.

NASA/JPL-Caltech/University of Arizona

Mesas and dunes stand out in the view snapped by HiRISE, one of the imagers aboard the agency’s Mars Reconnaissance Orbiter.

After nearly 20 years at the Red Planet, NASA’s Mars Reconnaissance Orbiter (MRO) has snapped its 100,000th image of the surface with its HiRISE camera. Short for High Resolution Imaging Science Experiment, HiRISE is the instrument the mission relies on for high-resolution images of features ranging from impact craters, sand dunes, and ice deposits to potential landing sites. Those images, in turn, help improve our understanding of Mars and prepare for NASA’s future human missions there.

Captured Oct. 7, this milestone image from the spacecraft shows mesas and dunes within Syrtis Major, a region about 50 miles (80 kilometers) southeast of Jezero Crater, which NASA’s Perseverance rover is exploring. Scientists are analyzing the image to better understand the source of windblown sand that gets trapped in the region’s landscape, eventually forming dunes.

“HiRISE hasn’t just discovered how different the Martian surface is from Earth, it’s also shown us how that surface changes over time,” said MRO’s project scientist, Leslie Tamppari of NASA’s Jet Propulsion Laboratory in Southern California. “We’ve seen dune fields marching along with the wind and avalanches careening down steep slopes.”

Watch highlights of images captured by HiRISE, the high-resolution camera aboard NASA’s Mars Reconnaissance Orbiter, including its 100,000th image, showing the plains and dunes of Syrtis Major.

NASA/JPL-Caltech/University of Arizona

The subject of the 100,000th image was recommended by a high school student through the HiWish site, where anyone can suggest parts of the planet to study. Team members at University of Arizona in Tucson, which operates the camera, also make 3D models of HiRISE imagery so that viewers can experience virtual flyover videos.

“Rapid data releases, as well as imaging targets suggested by the broader science community and public, have been a hallmark of HiRISE,” said the camera’s principal investigator, Shane Byrne of the University of Arizona in Tucson. “One hundred thousand images just like this one have made Mars more familiar and accessible for everyone.”

More about MRO

NASA’s Jet Propulsion Laboratory in Southern California manages MRO for NASA’s Science Mission Directorate in Washington as part of NASA’s Mars Exploration Program portfolio. Lockheed Martin Space in Denver built MRO and supports its operations.

The University of Arizona in Tucson operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado.

For more information, visit:

https://science.nasa.gov/mission/mars-reconnaissance-orbiter

News Media Contacts

Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov

Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov

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Dec 16, 2025

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Source Link One of NASA’s Key Cameras Orbiting Mars Takes 100,000th Image

Mars, Mars Reconnaissance Orbiter (mro), Planetary Environments & Atmospheres

NASA Orbiter Shines New Light on Long-Running Martian Mystery

November 25, 2025

5 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

The European Space Agency’s Mars Express orbiter captured this view of Mars’ south polar ice cap Feb. 25, 2015. Three years later, the spacecraft detected a signal from the area to the right of the ice cap that scientists interpreted as an underground lake.

ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO

Results from an enhanced radar technique have demonstrated improvement to sub-surface observations of Mars.

NASA’s Mars Reconnaissance Orbiter (MRO) has revisited and raised new questions about a mysterious feature buried beneath thousands of feet of ice at the Red Planet’s south pole. In a recent study, researchers conclude from data obtained using an innovative radar technique that an area on Mars suspected of being an underground lake is more likely to be a layer of rock and dust.

The 2018 discovery of the suspected lake set off a flurry of scientific activity, as water is closely linked with life in the solar system. While the latest findings indicate this feature is not a lake below the Martian surface, it does suggest that the same radar technique could be used to check for subsurface resources elsewhere on Mars, supporting future explorers.

The paper, published in Geophysical Research Letters on Nov. 17, was led by two of MRO’s Shallow Radar (SHARAD) instrument scientists, Gareth Morgan and Than Putzig, who are based at the Planetary Science Institute in Tucson, Arizona, and Lakewood, Colorado, respectively.

The observations were made by MRO with a special maneuver that rolls the spacecraft 120 degrees. Doing so enhances the power of SHARAD, enabling the radar’s signal to penetrate deeper underground and provide a clearer image of the subsurface. These “very large rolls” have proved so effective that scientists are eager to use them at previously observed sites where buried ice might exist.

This map shows the approximate area where in 2018 ESA’s Mars Express detected a signal the mission’s scientists interpreted as an underground lake. The red lines show the path of NASA’s Mars Reconnaissance Orbiter, which flew both directly overhead as well as over an adjacent region.
Credit: Planetary Science Institute

Morgan, Putzig, and fellow SHARAD team members had made multiple unsuccessful attempts to observe the area suspected of hosting a buried lake. Then the scientists partnered with the spacecraft’s operations team at NASA’s Jet Propulsion Laboratory in Southern California, which leads the mission, to develop the very large roll capability.

Because the radar’s antenna is at the back of MRO, the orbiter’s body obstructs its view and weakens the instrument’s sensitivity. After considerable work, engineers at JPL and Lockheed Martin Space in Littleton, Colorado, which built the spacecraft and supports its operations, developed commands for a 120-degree roll — a technique that requires careful planning to keep the spacecraft safe — to direct more of SHARAD’s signal at the surface.

Bright signal

On May 26, SHARAD performed a very large roll to finally pick up the signal in the target area, which spans about 12.5 miles (20 kilometers) and is buried under a slab of water ice almost 1 mile (1,500 meters) thick.

When a radar signal bounces off underground layers, the strength of its reflection depends on what the subsurface is made of. Most materials let the signal slip through or absorb it, making the return faint. Liquid water is special in that it produces a very reflective surface, sending back a very strong signal (imagine pointing a flashlight at a mirror).

That’s the kind of signal that was spotted from this area in 2018 by a team working with the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument aboard the ESA (European Space Agency) Mars Express orbiter. To explain how such a body of water could remain liquid under all that ice, scientists have hypothesized it could be a briny lake, since high salt content can lower water’s freezing temperature.

An antenna sticks out like whiskers from NASA’s Mars Reconnaissance Orbiter in this artist’s concept depicting the spacecraft, which has been orbiting the Red Planet since 2006. This antenna is part of SHARAD, a radar that peers below the Martian surface.

NASA/JPL-Caltech

“We’ve been observing this area with SHARAD for almost 20 years without seeing anything from those depths,” said Putzig. But once MRO achieved a very large roll over the precise area, the team was able to look much deeper. And rather than the bright signal MARSIS received, SHARAD detected a faint one. A different very-large-roll observation of an adjacent area didn’t detect a signal at all, suggesting something unique is causing a quirky radar signal at the exact spot MARSIS saw a signal.

“The lake hypothesis generated lots of creative work, which is exactly what exciting scientific discoveries are supposed to do,” said Morgan. “And while this new data won’t settle the debate, it makes it very hard to support the idea of a liquid water lake.”

Alternative explanations

Mars’ south pole has an ice cap sitting atop heavily cratered terrain, and most radar images of the area below the ice show lots of peaks and valleys. Morgan and Putzig said it’s possible that the bright signal MARSIS detected here may just be a rare smooth area — an ancient lava flow, for example.

Both scientists are excited to use the very large roll technique to reexamine other scientifically interesting regions of Mars. One such place is Medusae Fossae, a sprawling geologic formation on Mars’ equator that produces little radar return. While some scientists have suggested it’s composed of layers of volcanic ash, others have suggested the layers may include heaps of ice deep within.

“If it’s ice, that means there’s lots of water resources near the Martian equator, where you’d want to send humans,” said Putzig. “Because the equator is exposed to more sunlight, it’s warmer and ideal for astronauts to live and work.”

More about MRO

NASA’s Jet Propulsion Laboratory in Southern California manages MRO for the agency’s Science Mission Directorate in Washington as part of NASA’s Mars Exploration Program portfolio. Lockheed Martin Space in Denver built MRO and supports its operations. SHARAD was provided to the MRO mission by the Italian Space Agency (ASI).