Mars, although an arid planet today, still bears the vestiges of its past, a time when it was awash with water. Today, the Martian landscape is a thousand times drier than Earth’s most parched desert, yet intriguingly, ice still exists and flows, albeit slowly, across its surface. Thanks to NASA’s Mars Reconnaissance Orbiter, equipped with the High Resolution Imaging Experiment (HiRISE), the most potent camera ever dispatched to another planet, we now have a clear image of an icy flow captured from a staggering 184 miles above the Martian surface. This image, revealing the existence of ice beyond the frigid poles, is a testament to Mars’ enduring geological activity.
"The surface of Mars is strewn with glacier-like landforms," says Mike Mellon, a Mars geologist and co-investigator of the HiRISE project. He further explains that while surface ice deposits are mainly confined to the polar caps, evidence of slow, viscous flow is abundant in many non-polar regions of Mars. This ice, often forming on rocky debris within valleys and craters, moves slowly downhill, carrying along rock and soil from the surrounding landscape. Despite the gradual pace of this process, taking perhaps thousands of years or longer, it forms a network of linear patterns that reflect the history of ice flow on Mars.
Mars: A Cold, Dry Planet with a Trace of Ice Flow
In the realm of space exploration, Mars has always been a fascinating planet, particularly due to its history of abundant water. However, today’s Mars is 1,000 times drier than Earth’s driest desert. Despite this, Mars still harbors some ice, which flows, albeit slowly, on its surface.
Powerful Glimpses from NASA’s Mars-orbiting Satellite
The Mars Reconnaissance Orbiter, a satellite sent to Mars by NASA, is equipped with the High Resolution Imaging Experiment (HiRISE), dubbed as the "most powerful camera ever sent to another planet." This advanced piece of technology has provided planetary scientists with rich images of the Martian surface, including a recent snapshot of a glacier-like icy flow from 184 miles above Mars’ surface. This ice isn’t just confined to Mars’ frigid poles.
Mike Mellon, a Mars geologist and co-investigator of the HiRISE project, has shed light on this phenomenon, stating that the Martian surface is riddled with glacier-like landforms. He explains, "While surface ice deposits are mostly limited to the polar caps, patterns of slow, viscious flow abound in many non-polar regions of Mars."
Tracing the Movement of Ice on Mars
This slow-moving ice is known to form on rocky debris within valleys and craters. Mellon further explains, "As ice flows downhill, rock and soil are plucked from the surrounding landscape and ferried along the flowing ice surface and within the icy subsurface." Though this process is gradual and can take thousands of years or more, it creates a network of linear patterns that reveal the history of ice flow on Mars.
Even after the ice melts or evaporates, the rock flows remain, leaving signs of Mars’ diminished, yet still active, geologic activity.
Mars’ Past as a Water World and the Search for Primitive Life
Contrasting with the current state of Mars, the planet was once a water world, with lakes covering the land and streams running through river deltas. In present times, NASA’s Perseverance rover is exploring the river delta in Mars’ Jezero Crater, with hopes of finding evidence of past, primitive life, if it ever existed.
The discovery of ice flow on Mars provides an intriguing peek into the planet’s geologic activity and history. It reminds us that despite Mars’ current arid state, it was once a planet teeming with water. As scientists continue to delve into Mars’ past using advanced technology, the possibility of uncovering signs of primitive life becomes ever more tantalizing. These findings underscore the importance of continued space exploration and research, as we strive to understand our neighboring planets and, in the process, our own.