Curiosity rover spots ‘mini-hoodoos’ on Mars

Curiosity rover: 2 small spikes of rock protruding above surrounding rock and sand.
NASA’s Curiosity rover spotted these unusual-looking stick-like spikes of rock on Mars on May 17, 2022. They’re reminiscent of hoodoos on Earth, but much smaller. Mission scientists say they’re probably columns of harder rock cracks in bedrock, left behind after surrounding softer rock was eroded away by wind and sand. Image via NASA/ JPL/ Caltech/ MSSS/ Science Alert.

Curiosity rover finds odd little rock spikes

Over the years, rovers on the red planet Mars have come across lots of interesting rock formations, including towering cliffs, “pavement stones” and rocks covered in round nodules and mineral veins, to name a few. And some of the most fascinating formations have also been the most delicate, often very thin or spindly, looking like the slightest touch will break them. Wind and sand erosion create them in the thin Martian atmosphere. Now, the Curiosity rover has discovered another great example of a fascinating and delicate Mars rock formation. They are small stick or spike-like structures protruding from the ground, reminiscent of hoodoos on Earth, but much smaller.

Curiosity took the image at the top of this page on May 17, 2022. The SETI Institute and others later shared them on Twitter, sparking interest and debate as to what they might be.

So, what are they?

They look like petrified sticks or branches, or even frozen streams of water. But Curiosity mission scientists say they are indeed eroded rock formations. The rovers have seen similar structures before, although not usually pointing upward so dramatically. These recent ones do look out of place among the surrounding red Martian rocks and sand.

Mission scientists say they likely formed from harder sedimentary rock that used to fill cracks in softer bedrock. Wind and sand eroded the softer rock away over billions of years, leaving the harder material behind. That harder material forms the remaining spikes we see today. These just happened to be more vertical in the surrounding rock to begin with. They remained that way due to the exceedingly thin atmosphere not being able to knock them over. On Earth, with our thicker atmosphere, such delicate formations probably wouldn’t last nearly as long.

Many tall vertical rock formations in canyon with blue sky and clouds above.
View larger. | An example of hoodoos on Earth. These are in Bryce Canyon National Park, Utah. Although much larger than their Martian counterparts, they are thought to form in a similar manner. Image via Luca Galuzzi/ Wikipedia (CC BY-SA 2.5).
Tall spikes of rock on slope, with blue sky above.
View larger. | Hoodoos in Devil’s Town, Serbia. Image via Dimo Dimov/ Wikipedia (CC BY-SA 2.0).

Analogies on Earth

There are similar structures on Earth, although they tend to be much larger. Their larger size is also why they’ve been able to last for millions of years. Hoodoos are a good example. These are tall, thin spires of rock, typically found in dry environments. They are common in Utah and southern Serbia, for example. Unlike their Martian counterparts, earthly hoodoos can be as tall as a 10-story building!

But just like the spikes on Mars, they form when softer sedimentary rock is eroded away, leaving the spike-like core of harder rock still standing.

The ‘flower’ and ‘spoon’

Last February, Curiosity imaged another cool little rock formation. This one looks like a budding flower or piece of coral, but alas, is also just a wind-sculpted rock.

In 2015, the rover came across a brittle-looking rock formation that looks just like a spoon. Long and thin, the “handle” end is attached to a larger, flat piece of rock, and almost appears to be floating! It looks rather precarious, suspended above the ground like that.

These are just two other examples, but there are more. In many places, the various rovers have seen sedimentary rocks composed of many thin layers, as well as flakes of rock. Some layers and flakes are so delicate-looking – almost paper-thin – they would seemingly crumble if just lightly touched.

Small rock formation with several branching arms surrounded by sand.
View larger. | The “Mars flower” seen by Curiosity on February 24, 2022. While resembling a budding flower or piece of coral, it is another example of a delicately wind-eroded rock. Image via NASA/ JPL-Caltech/ MSSS.
Spoon-shaped rock attached to a larger flat rock on reddish terrain.
View larger. | This spoon-like object was seen by Curiosity in 2015. Another delicate rock formation sculpted by the thin winds. Image via NASA/ JPL-Caltech.

Curiosity rover exploring the foothills of Mount Sharp

Curiosity is currently meandering through mesas and foothills at the base of Mount Sharp, first seen from a distance. It is seeing some specular scenery as it gradually makes its way up the mountain.

Bottom line: NASA’s Curiosity rover has spotted some intriguing stick-like rock spikes, resembling hoodoos on Earth, but much smaller. How did they form? Mission scientists say erosion of softer rock around columns of harder rock (the spikes) is likely the cause.

Via Science Alert

June 14, 2022

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