If a rock falls on Mars, and no one is there to see it, will it leave a mark? Yes, and it’s a beautiful herringbone-like pattern, new research reveals. Scientists have now discovered thousands of tracks on the red planet made by jumbled rocks. The team showed subtle v-vron-shaped mounds of sand and dust framing the tracks, and most of it faded within a few years.
Rockfalls have been detected elsewhere in the solar system, including on the moon and even a comet. But a big open question is the timing of these processes on other worlds – are they ongoing or do they mostly happen in the past?
A study of these ephemeral features on Mars, published last month in Geophysical Research Letters, says that such rock tracks could be used to identify recent seismic activity on the red planet. Ingrid Daubar, a planetary scientist at Brown University who was not involved in the study, said this new evidence shows that Mars is a dynamic world contrary to the notion that all geology interesting of the planet happened before. “For a long time, we thought Mars was this cold dead planet.”
To make this discovery, Vijayan, a planetary scientist at the Physics Research Laboratory in Ahmedabad, India, who uses a unique name, and his colleagues studied thousands of shapes image of the equator of Mars. The image was taken between 2006 and 2020 using the High Resolution Imaging Science Experiment (HiRISE) camera aboard NASA’s Mars Reconnaissance Orbiter and reveals details as small as 10 inches.
“We can distinguish individual rocks,” says Dr. Vijayan.
The team manually searched for chain-like features – a narrative signature of a rock lying down – on the inclined walls of the impact craters. Dr. Vijayan and his colleagues have discovered more than 4,500 such rock tracks, the longest of which spans more than a mile and a half.
Dr Vijayan said: “Sometimes the tracks change direction and sometimes new tracks suddenly branch. Such altered tracks are likely evidence that a rock has disintegrated in mid-autumn and its offspring continue to bounce downhill.
Nearly a third of the tracks that the researchers didn’t include in the original images, meaning they must have been formed since 2006. The bouncing tracks of all of these young tracks are framed by a V-shaped pile Martian regolith. The researchers propose that the material, which Dr Vijayan and his colleagues nicknamed the “falling rock”, would be removed each time a rock impacted the surface, the researchers said. offer.
And that rock’s fall is only fleeting: By following the same tracks in images obtained at different times, the team found that the rock’s fall material tends to only visible for about 4 to 8 years. The researchers suggest that the wind is constantly sweeping on the surface of Mars redistributes sand and dust and removes the ejection block.
The team suggested that, because the rock was falling out so quickly, seeing it implied that a rock had recently been removed. And a common cause of landslides, on Earth and elsewhere, is seismic activity.
Dr. Vijayan and his colleagues found that about 30% of the rock marks in their sample with nozzles falling from the rock were concentrated in the Cerberus Fossae region of Mars. This is more than expected, the researchers say, because the area covers just 1% of the study’s area. Dr Vijayan said: ‘The surrounding craters have a lot of falling rocks. “Some of them even have multiple falls in the same place.”
That makes sense, said Alfred McEwen, a planetary geologist at the University of Arizona and principal investigator of HiRISE, not involved in the study. Geographical location near Cerberus Fossae, namely Tharsis . Volcanic Region, there is a tendency for the area to be seismically active. Dr McEwen said: ‘These massive dense rocks were deposited on the surface creating pressure throughout the surrounding crust of Mars.
In the future, Dr. Vijayan and his colleagues plan to extend their analysis to the polar regions of Mars. Dr McEwen said the HiRISE camera is expected to be used, although the device is significantly past its design time. “HiRISE is still going strong.”
https://www.nytimes.com/2022/01/22/science/mars-boulders-earthquakes.html Bounce Boulders Points To Quakes On Mars