Mars is Still an Active World. Here’s a Landslide in Nili Fossae

Since the 1960s and 70s, scientists have come to view Mars as something of a “dead planet.” As the first close-up images from orbit and the surface came in, previous speculation about canals, water, and a Martian civilization were dispelled. Subsequent studies also revealed that the geological activity that created features like the Tharsis Mons region (especially Olympus Mons) and Valles Marineris had ceased long ago.

However, in the past few decades, robotic missions have found ample evidence that Mars is still an active place. A recent indication was an image taken by the Mars Reconnaissance Orbiter (MRO), which showed relatively fresh landslides in a crater near Nili Fossae. This area is part of the Syrtis Major region and is located just north of the Jezero Crater (where the Perseverance rover will be landing in six weeks!)

The landslide was captured as a part of a larger image (shown below) acquired by the MRO’s Context Camera (CTX) on September 21st, 2018. The image covers an area that measures close to 5 km (3 mi) across and was taken while the MRO was 284 km (177 mi) above the surface. From all indications, this appears to have been the result of material in the crater wall becoming unstable.

Landslides in a crater near Nili Fossae on Mars Credit: NASA/UofA HiRiseteam/MRO

The CTX is designed to provide large-scale background views of the terrain around smaller rock and mineral targets that are studied by other instruments on the MRO – like the High-Resolution Imaging Science Experiment (HiRISE) and the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). It is also responsible for taking mosaic images of large areas to help with landing site selection for future missions.

Last, but not least, the CTX is responsible for monitoring locations on the Martian surface for possible changes over time. That is precisely what this image showed inside a crater wall near Nili Fossae, which experienced an infall of material since it was last photographed. The HiRISE camera also noted a similar infall of wall material on the crater’s other side.

These features are the result of what geologists characterize as “mass wasting processes” (or slope processes). This term is rather broad and deals with the downhill movement of rocks and debris, including large landslides, debris avalanches, rockfalls, debris flows, and soil creep. On Mars, previous images have shown a full range of these activities, ranging from giant rock avalanches to tiny slumps and single rockfalls.

As noted, the crater captured in the CTX image lies just northwest of the Jezero Crater, which is the landing site of the Perseverance rover. This site was selected because of the delta fan located near the western wall of the crater. On Earth, these features form in the presence of moving water which slowly deposit sedimentary material over time.

Orbital picture of the Jezero crater, showing its fossil river delta. Credit: NASA/JPL/JHUAPL/MSSS/BROWN UNIVERSITY

Like many features in the Gale Crater, which the Curiosity rover has been studying since it landed there in 2012, this feature is evidence that Mars had flowing water on its surface billions of years ago – in the form of rivers, lakes, and even a large ocean that covered its Northern Lowlands. If life also emerged in this period, then one of the most likely places the fossilized remains would be is within delta fans.

Regardless of whether or not life once existed on Mars (or still does!) it is clear that planet is very much alive. Its geological features are a testament to both the past and present forces that actively shape it. Understanding these forces and the affect they have on the landscape are an essential part of our efforts to characterize the Martian environment (and maybe even live there someday).

Further Reading: University of Arizona

Matt Williams

Matt Williams is a space journalist and science communicator for Universe Today and Interesting Engineering. He's also a science fiction author, podcaster (Stories from Space), and Taekwon-Do instructor who lives on Vancouver Island with his wife and family.

Recent Posts

Lunar Infrastructure Could Be Protected By Autonomously Building A Rock Wall

Lunar exploration equipment at any future lunar base is in danger from debris blasted toward…

7 hours ago

Why is Jupiter’s Great Red Spot Shrinking? It’s Starving.

The largest storm in the Solar System is shrinking and planetary scientists think they have…

14 hours ago

ESA is Building a Mission to Visit Asteroid Apophis, Joining it for its 2029 Earth Flyby

According to the ESA's Near-Earth Objects Coordination Center (NEOCC), 35,264 known asteroids regularly cross the…

20 hours ago

The Most Dangerous Part of a Space Mission is Fire

Astronauts face multiple risks during space flight, such as microgravity and radiation exposure. Microgravity can…

22 hours ago

Stars Can Survive Their Partner Detonating as a Supernova

When a massive star dies in a supernova explosion, it's not great news for any…

1 day ago

Swarming Satellites Could Autonomous Characterize an Asteroid

An asteroid's size, shape, and rotational speed are clues to its internal properties and potential…

1 day ago