What Left This Long, Winding Trail Across Mars? NASA’s Orbiter Has the Answer

From ancient river valleys to towering dust devils, Mars is a mysterious planet. However, one of its most puzzling characteristics has been the numerous miles-long, winding trails that traverse its surface. What could have created these strange marks? Thanks to NASA’s Mars Reconnaissance Orbiter (MRO), we now have an answer.

The Curious Case of the Martian Tracks These dark, meandering streaks were seen by scientists in orbital images for years. At first glance, they resembled:

Dried-up riverbeds (but lacked the branching patterns of water erosion).

Lava flows (but appeared too narrow and inconsistent).

Dust devil tracks (but these are usually shorter and more chaotic).

The most compelling theory? Rolling boulders.

The Orbiter of NASA reveals the truth Using the High-Resolution Imaging Science Experiment (HiRISE) camera aboard MRO, researchers studied these trails in detail. They found:

Boulders at the end of many trails, suggesting they had tumbled downhill.

Fresh tracks appearing in newer images, indicating ongoing activity.

No signs of liquid water or volcanic flow, ruling out other explanations.

The conclusion? These trails are made by boulders rolling down Martian slopes, leaving behind dark scars as they disturb the dusty surface.

Why Do the Boulders Roll?

Mars has weaker gravity than Earth (about 38% as strong), meaning rocks can travel farther once set in motion. Possible triggers include:

Marsquakes (seismic activity cracking rocks loose).

Thermal expansion and contraction (temperature changes destabilizing slopes).

Wind erosion (undermining rocks to the point where they fall apart) Why Are the Trails So Dark?

Mars lacks vegetation or rain to erase these marks, unlike Earth. A boulder that rolls: Exposes darker subsurface material beneath the reddish dust.

Creates a contrast that can last for years before fading.

What This Tells Us About Mars

Studying these trails helps scientists understand:

Martian geology—how rocks erode and move over time.

Surface processes—how the landscape is shaped by wind, temperature, and gravity. Potential hazards for future rovers or human missions (avoiding unstable slopes).

Conclusion: A Simple Answer to a Martian Puzzle

What once seemed like a mysterious phenomenon has a straightforward explanation: Mars’ boulders go on long, rolling journeys, leaving behind ghostly trails. Thanks to NASA’s MRO, we now know that even on a seemingly dead world, the landscape is still changing—one tumbling rock at a time