What Curiosity found out about Mars' past
Some rocks of the Red Planet, taken from the NASA rover, behave like "time capsules", showing phenomena that can be traced back to climate change
(image: Nasa / Jpl-Caltech / Msss) So much, long ago there were lakes and streams on Mars, an environment in which it would have been possible to see life as we know it. But for millions of years it has been a desert of rocks and sand, cold, bombarded by radiation. Of the ancient lakes the basin and all that its sediments can tell us remained. A story that today appears even more surprising: the analyzes of the rocks in the Gale crater made by Curiosity, the NASA rover on a mission to the planet, revealed that the minerals are not all the same, but that something has altered some of them, also deleting any clues. of microorganisms that may have populated the Red Planet. And the discovery is not at all disheartening.What Martian rocks tell us
As happens on Earth, rocks on Mars also keep track of the changes that occur on the planet, like a sort of capsule weather . This is why scientists believe that studying minerals could reveal the history of the Red Planet and, perhaps, help us find traces of past life.Comparing two rock samples taken from the Curiosity rover less than 400 meters away from each other inside the Gale crater, NASA experts have made a surprising discovery. Despite being the same age, the two rocks have a different composition: one has half of clayey minerals than expected, replaced by minerals rich in iron oxide (which is what gives it the red color). A sign that something has changed the mineralogy of sediments, also erasing what they could tell.
Salt water
What could have happened? Based on what is happening on Earth, it is plausible to scientists that once the original lake dried up, the interactions between the sediments and super saline water gave rise to a process (known as diagenesis) that changed mineralogy and the traces of previous history have been erased. An unexpected discovery for scientists, but which constitutes a further clue to the climate changes that Mars has undergone.Nothing is lost
No discomfort for the loss of any study material, including any traces of Martian life. "While diagenesis may have erased the signs of life in the original lake, it may have created chemical gradients necessary to support life underground, so we are really excited to have discovered it," commented John Grotzinger of the California Institute of Technology and among others. authors of the study, recalling the "underground biospheres" that are also formed on Earth. "These are excellent places to look for evidence of ancient life and evaluate habitability," he added.Curiosity's findings will also guide the goal setting of Perseverance, teaching scientists to recognize sites with more suitable for collecting samples to increase the chances of finding traces of life.
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Topics
Aliens Curiosity Mars Perseverance globalData.fldTopic = "Aliens, Curiosity, Mars, Perseverance"
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