Weird Rocks on Mars

 Perhaps you have seen videos or pictures of rocks very carefully stacked as an artistic work. They may even look impossibly balanced. 

Balanced Rocks. Wikipedia.

    Or you may have seen so-called balancing rocks, with one huge boulder precariously sitting on a tiny point on top of another large boulder. These terrestrial balancing boulders weren’t created by humans, but rather by wind and water erosion.

Balancing rocks formed by erosion. Nevada Traveler

Scientists studying the images and data sent back by the Perseverance rover on Mars found an unusual sight. It appears to be three or four rocks neatly stacked one on top of the other. It rather resembles a hamburger with an oversized patty or an undersized bun. The patty in the middle looks as if it broke because the bun was too small. The rocks fit together so perfectly that they look as if they were stacked by human hands. Scientists attribute the stacked appearance to wind erosion of a single rock. Some say it looks more like water erosion, but there hasn’t been any surface water on Mars for perhaps 3 billion years.

Staxcked rocks on Mars. NASA/JPL/Cal Tech

This find by Perseverance isn’t the only weird rock discovered on the surface of Mars. Perseverance photographed a rock with stripes or striations on it. It looks to the scientists studying the images and data from the rover to be volcanic in origin. It appears to have fallen from a layer of similar rock farther up the slopes of Jezero crater that Perseverance has been exploring since it landed. Athanasios Klidaras, a PhD student in planetary science at Purdue University, wrote in a statement on NASA's Science website, "Our knowledge of its chemical composition is limited, but early interpretations are that igneous and/or metamorphic processes could have created its stripes."

Stripped rock on Mars. NASA/JPL/Cal Tech

One of the stranger rocks Perseverance imaged the researchers nicknamed "St. Pauls Bay." It is covered with hundreds of millimeter-sized, dark grey spheres. Some of them have tiny pinholes in them. Scientists believe these spheres to be concretions formed by the interaction of groundwater circulating through pores in the rock. It is also possible they were formed by volcanic activity. "Each of these formation mechanisms would have vastly different implications for the evolution of these rocks, so the team is working hard to determine their context and origin," the mission team said in the statement. "Placing these features in geologic context will be critical for understanding their origin and determining their significance for the geological history of the Jezero crater rim and beyond."

Studded rock on Mars. NASA/JPL/Cal Tech

While Perseverance’s main job is to look for evidence of past life on Mars, which it has yet to find, it is finding that the environment was once, long ago, conducive to life. It may yet find fossilized bacterial remains like those we have found on our planet.

 

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published there, I post that same column to my blog page.

This is reprinted with permission from the Oklahoman and www.Oklahoman.com.