While the colorful deposits on Mars’ rocks aren’t a new discovery per se, the sheer number of purple spots made scientists scratch their heads this time.
“We haven’t seen these special purple layers on previous rover missions,” he says. Bradley Garcinski from Purdue University, who also presented a Layer Analysis Foot. Garczynski studied purple varnish using a pair of cameras Mastkam-Z, which are “actually the scientific eyes of the rover,” he said. Using different filters on cameras, which block out certain wavelengths, Garczynski got an initial idea of the composition of rocks in photographs. determination.
Olila and her colleagues studied the layers in more detail using the . file SuperCam by determination, which uses a laser beam to vaporize a piece of the rock’s surface, thus checking the chemical composition of the rock. With each “laser shot” a crack could be heard and a small hole was created in the stone. A microphone on the rover picks up this sound, so scientists can hear as the laser beam drills through a layer of varnish and then into the underlying rock. POPs contain information about the properties of rocks, such as their hardness.
Preliminary analyzes of this data show that the purple layers are much softer and also have a different chemical composition than the underlying rocks. According to Garczynski, images from Mastcam-Z show that the layers contain a lot of iron oxide. According to Ollila, SuperCam analyzes show that it is rich in hydrogen and sometimes even magnesium.
The presence of hydrogen seemed to indicate that water played an important role in the formation of stains. Iron oxide also refers to this and in this sense it can be compared to rust on a bicycle that has been standing in the rain for a long time.
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Further research could provide more information about the red planet’s wet past, answer the question of how long Jezero Crater has been a lake and possibly its chemical makeup. “Having these layers can be an important part of that story,” Garcinsky says.
But the location where the purple spots were found is still somewhat mystifying. way that determination Currently follows, it does not pass through the sediments in the lake but along the rocks that formed By cooling the magma. It is still not clear how this rock ended up in its current location – the bottom of an ancient lake – and when exactly it came into contact with the water. “If you had to guess where this group of rocks would appear in the Jezero Crater, you wouldn’t pick that location,” Lanza says.
So far, the team has only been able to take a few soil samples and have run into many hurdles in the process. According to Ollila, the chemical results of the SuperCam and the changes in sounds generated by the laser beam do not appear to be identical. Distinguishing the chemical signatures of layers, bedrock and red dust scattered on Mars has proven very difficult. The relatively strong Martian winds also make it difficult for scientists to properly assess the laser blasts. “Mars doesn’t make it easy for us,” Lanza says.
On Earth, the layers on rocks are often associated with life forms, which means that Martian varnish is of particular interest to astrobiologists. Marnucha explains that microbes can survive in tiny holes and cracks in rocks under extremely hostile conditions. There they find nutrients, shelter from sunlight, and moisture that would evaporate onto the dry surface of the bones. Some of these microbes leave layers on the rocks by picking up minerals dissolved in water from the rocks.
On Mars, purple spots can also Recorded the presence of ancient microbes By protecting the fragile organic structures of these life forms from the sun’s rays.
The first indications of varnish layers on Martian rocks were discovered as early as the mid-1970s during Vikings missions explore. But, according to Marnusha, it took a lot of thieves on the road to determine if it was actual varnish or just a discoloration of the rocks.
It was especially exciting Detection of dark layers containing manganese In the crater of the volcano Gale, where the rover curiousity He is currently surveying the surface of Mars. The Door curiousity The strata in which they are found are very reminiscent of the “desert varnish” here on Earth, which usually contains countless organisms. In a recent review of desert varnishes in the United States, scientists found that they contain “the full range of bacteria known to be resistant to radiation,” he says. Chris Yeager, a microbiologist and ecologist at Los Alamos National Laboratory.
Yeager and colleagues linked the high manganese content in desert varnish to certain types of blue-green algae, which metal accumulates To protect itself – a bit like sunscreen – from harmful solar radiation.
Lanza says the levels of manganese in the layers of Jezero crater aren’t high enough to classify it as a “desert varnish,” but that doesn’t mean it’s unrelated to ancient microbial life. “Who knows what Martian microbes do?”
The team hopes to decipher the chemical makeup of the purple spots and search the Martian crust for organic materials that could indicate the presence of microbes. In order to definitively determine the origin of the purple spots, the rock samples themselves must be brought to Earth for study in laboratories.
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On its way through Jezero crater exercises determination Rock samples from Mars rocks, wrapped in metal tubes and left on the surface of the Red Planet so it can be picked up and brought to Earth during a future mission. Although the purple layers are delicate, Ollila hopes they will survive the digging well so that scientists can analyze them in detail in the future.
Meanwhile, the team follows determinationHe searched the crater of Jezero with a lot of tension. “We just started this research,” Lanza says. “This is just one of many types of materials that we are likely to encounter, so I think we have a lot of discoveries ahead.”