Immigrants from Mercury's North Pole

In the "sand sandwich" under the Martian Arctic ice sheet, scientists used ground penetrating radar to detect that a large amount of water was stored in frozen form. There is a lot of ice in the reservoir. If it melts and covers the surface, the whole planet will be transformed into "Mercury" from now on.

Illustration: (cover of Mars North Pole)

Stefano Nerozzi, Ph.D. student at the University of Texas at Austin: "This is really a long time for us!"

Located two kilometers below the North Pole of Mars, the "Dome Room" is actually a huge storage room, consisting of a multi-layer mixture of sand and solid water, which took hundreds of millions of years to form. Before the publication of this article, only a large amount of dark sand and a small amount of frozen water were observed in the dominant rock formations on the surface of Mars, so scientists estimated that there were only sand piles and solid water with a volume never exceeding 50% in the dome.

According to the scanning results of radar orbit, there should be more water ice in the dome than sand, wrote an article in the published Geophysical Research Weekly. This reversible conclusion also explains why there is the third largest reservoir besides the polar ice sheet on this red planet.

These observations are all from an instrument called SHARAD“Shada "on NASA's Mars Reconnaissance Orbiter. Nerozzi's team determined the internal structure and composition between domes by using radar waves emitted by SHARAD that can penetrate the surface.

The observation data also reveal that the horizontal plates rich in ice actually alternate with sand layers. In terms of volume, the distribution of water ice accounts for 6 1%-88% (evidence that the dome layer is composed of a large number of frozen water). In the publication, it is worth noting that if this discovered polar ice water melts and rushes to the surface, its water volume can cover the whole of Mars, even down to the depth of 1.5 meters. That's not just a little water on Mars!

Illustration: This composite photo comes from alternating layers of ice and sand on the surface of Mars. Light color represents water ice, and dark blue represents sand.

SHARAD's data show that the frequency and volume of ice increase with the distance from the North Pole. For example, researchers have detected that there are two layers of sand with a width of 40 kilometers on the ice layer with a depth of 50- 100 meters in an area.

A paper holds that these buried structures should be the products left over from the predecessor of ice sheet contraction during the high temperature period. In other words, the whole dome is actually a history book that records the climate of Mars! These ice layers are like tree rings, which can tell us how the ancient polar caps have expanded and contracted over the years. Mars, like the earth, has experienced many ice ages. When the climate is mild, sand will cover the shrinking ice and block the sun. Therefore, ice water will not evaporate into the atmosphere.

In the conversation between Nerozzi and Gizmodo, it is mentioned: "The only conjecture that can keep our results abreast with all previous research results is that the dome of Mars is composed of alternating borneol, and the remains of the front polar cover act as a protective blanket to protect the sand layer where the old polar ice completely recedes." "The unexpected joy that comes with this conjecture is that we have a record of how the polar ice sheet extended hundreds of millions of years ago."

Before the discovery of this study, scientists thought that the early ice sheets no longer existed, but SHARAD's data did not predict this.

"These results are significant because they confirm that there was a climate circle in the Arctic of Mars in the past," Matthew Chojnacki, a planetary scientist at the University of Arizona, wrote in an email to Gizmodo, who was not involved in the study. "For thousands of years, or earlier, it was the wind that cast a huge sand dune product, and then repeatedly buried the ice to varying degrees. This kind of sand ice accumulation also exists on the earth, but I never thought that there would be such a huge case in the Arctic dome of Mars. "

This discovery also tells us the distribution of other solid water on Mars, especially in low latitudes. Jack Holt, one of the authors of this study and a researcher at the University of Arizona, used SHARAD to confirm that there are a large number of glaciers in the middle latitudes of Mars. One of them is as big as three Los Angeles. Almost all of these glaciers are composed of solid water, but they can't avoid being covered by some surface materials.

"Surprisingly, the total volume of water locked in the polar ice bank is almost the same as that of glacier water and ice water known in the low latitudes of Mars, and they all originated in the same period," said Holt of the University of Texas Press.

We now know that Mars still contains a lot of water resources. Theoretically, this bodes well for future residents who need these precious liquids.

"These borneol layers may be extremely pure, and there is almost no dust pollution. However, because the domes are buried 2 kilometers thick under the ice sheet, it is not an easy task to reach them. " Nerozzi also said: "In contrast, it is much more convenient to extract pure ice water from the surface of the ice sheet. If you want to drink or process it into rocket fuel, dust pollutants and a little salt in ice water need to be filtered out. "

Nerozzi continued his dome research and used Sharad to read the evolution records of polar ice sheets in the past. According to the existing geological and climatic data, he may be able to restore the formation history of the entire dome again.

Dr. Nerochi also said: "This discovery not only allows us to discover how the water on the earth was distributed in the past,

This also shows that there may have been a lot of life-sustaining liquid water near its equator. "

reference data

1. Wikipedia

2. Astronomical terminology

3.gizmodo- George Dvozski-Gene 6

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