(ORDO NEWS) — The main condition for the emergence of extraterrestrial life on a particular planet is the presence of water on it.
On Mars, as you know, there was once a lot of water, but at some point the planet lost its magnetic field, and after it the atmosphere, as a result of which the water evaporated. But why did scientists decide that there was a lot of water on the Red Planet, because now there is practically none there?
This is evidenced by indirect signs that scientists continue to look for and carefully study. Typically, such signs are present in rocks and soil, where certain structures and minerals could only be formed by contact with water.
Another such evidence of the existence of water on Mars was found in the faults that are in the Gale crater and beyond.
The rocks of Mars contain opal
Scientists have noticed that around some faults there are “halos” of lighter rocks. They give the surface of the Martian crater Gale a semi-precious sheen.
But how and why did these “halos” arise? According to new data obtained thanks to the Curiosity rover, as well as the ChemCam apparatus, rocks rich in opal have light tones.
When scientists discovered light streaks in new images taken by the Curiosity rover, they began to carefully study old photos from the archives, which were once also taken by the Curiosity rover, but in a different place.
It turned out that similar “halos” were also imprinted on them, although on completely different rocks. Obviously, a similar picture is observed not only in the Gale crater and in its vicinity, but also in other parts of Mars.
Using new analysis technologies, including the Dynamic Albedo of Neutrons, or DAN, neutron spectrometer, the researchers found that halos in different parts of the planet are not only similar in appearance, but also similar in composition.
They contain a lot of silica and water.
What is opal and how did it originate on Mars
Opal is a mineraloid, that is, a natural substance approximately homogeneous in chemical composition and physical properties, the basis of which is amorphous silica.
The water content of opal can reach 30%. The team reported this in their study, which was recently published in the Journal of Geophysical Research.
Why is the discovery of opal on Mars of great importance for science and provides a lot of new information about the Red Planet?
Earlier, we already talked about the fact that, having discovered manganese oxide in the rocks of Mars, scientists mistakenly made the wrong conclusions about the presence of a large amount of oxygen in the planet’s atmosphere.
However, there can be no mistake with opal – it could only appear if there was water on the surface of the planet.
The fact is that this mineral, or mineraloid, occurs when silica is dissolved in water like sugar or salt. As you know, when water contains a lot of salt, the latter begins to settle at the bottom.
The same thing happens with silica. Therefore, on Earth, opal is often present at the bottom of lakes and oceans. In other words, the presence of opal is strong evidence that the Red Planet was once covered in water.
Are the chances of life on Mars increasing?
Recently, scientists have discovered traces of a magnetic field on Mars that has existed for much longer than previously thought. This suggests that there was enough time on the planet for life to have time to originate.
The current study also raises the chances of life beginning, as it shows that water has existed on Mars for longer than science previously thought (the planet is believed to have “dryed up” between 4.1 and 3.7 billion years ago).
Water remained in the rifts long after the lake in Gale Crater dried up, the researchers report. Moreover, scientists have found that the faults form an extensive, interconnected network.
All this suggests that they could serve as a refuge for bacteria, protecting them from harsh conditions and providing a favorable environment. It is possible that life continued to exist there even into the modern geological period of the Red Planet, which began 2.9 billion years ago.
The team now proposes that more attention be paid to cracks that are rich in opal. They may help to better understand the planet’s aquatic past. In particular, scientists propose to collect geological samples here.
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