Mars has found a lot of water, which is easier to develop near the equator and may even preserve ancient creatures.

If human beings intend to emigrate to extraterrestrial planets, they must first know whether these places have livable conditions. For example, Mars, which is very close to us, once had lakes and rivers, and it was probably as livable as the earth. But now it has become dry and cold, and it is no longer suitable for life. Therefore, if human beings want to immigrate to Mars, they need to solve some basic needs, such as oxygen and water.

On May 15, the "Tianwen-1" landing patrol successfully landed in the pre-selected landing zone in the southern part of Mars Utopia Plain, starting the first Mars exploration mission in China, and discussing the long-term transformation of Mars and the prospect of establishing a second habitat for human beings with a large number of immigrants in the future. In addition, the "Tough" rover that landed on Mars in the United States also successfully produced oxygen on Mars by its own oxygen-making device. If water is found again, the construction of Mars habitat is just around the corner.

Just as people were struggling to find it, on February 5, 2002116 5438, the European Space Agency suddenly announced that the Mars exploration project jointly implemented by the agency and the Russian National Aerospace Corporation had found an unusually rich hydrogen content in the center of Mars Mariner Valley, nicknamed the Grand Canyon of Mars. The canyon is more than 4,000 kilometers long, 200 kilometers wide and 10 kilometers deep, which is ten times longer and five times deeper than the Grand Canyon of the Earth. In addition, Mariner's Valley is huge, making it the largest canyon in the solar system.

Above: Digital terrain model of Mariner Valley.

This discovery shows that there is a lot of water about one meter below the surface in the central area of Mars Mariner Valley, which may exist in the form of ice or water-bearing minerals. It is said that this aquifer is equivalent to the whole area of the Netherlands. These findings are attributed to the new data of the high-resolution superheated neutron detector (FREND) on the micro gas orbiter (TGO) operated by the European-Russian joint exploration project. Researchers say that it is because neutrons can be detected that people can see the hydrogen content in the soil one meter below the surface of Mars. Hydrogen is one of the two elements that make up water.

Above: Effect diagram of trace gas orbiter.

If all the hydrogen they detect exists in the form of water ice, then this precious compound may account for as much as 40% of the near-surface materials in this area. However, FREND may also detect water embedded in local minerals, although scientists think this is less likely than ice.

Above: Mariner Valley on the surface of Mars under the lens of Viking orbiter.

It is worth noting that this is not the first time that people have found water on Mars. In June, 200212002, NASA announced that by analyzing the radar data of the orbiter of the European Space Agency Mars Express, dozens of bright reflection areas were found around the South Pole of Mars. The depth of this area is about 1.5km below the surface, but on earth, such a bright reflection area can only be liquid. This means that there is water in the south pole of Mars. But this discovery is more meaningful than ever.

Above: The principle of radar detecting shallow structures.

Why is the water found this time more meaningful?

Because the difference is that the sailor's valley where water was found this time is near the equator. As we all know, the atmosphere of Mars is very thin, and the air is full of dust, including particles with a diameter of 1.5 micron. It is estimated that the pressure of Mars is between 0.4 and 0.87 kPa, which is equivalent to 1% of the measured sea level of the earth.

The thin atmosphere of Mars, coupled with its further distance from the sun, makes its surface temperature lower than that we can experience on earth. According to statistics, the average temperature of this Mars is only -46℃. In winter, the temperature in polar regions is as low as-143℃, while in summer, the temperature at the equator can be as high as 35℃ at noon. Therefore, compared with the cold polar regions of Mars, the temperature near the tropics is milder, which makes it possible for a small part of the water here to exist in liquid form, so it may be better to collect it.

Above: Mars polar ice sheet.

More importantly, if this kind of water exists like permafrost on our earth, it is likely to seal up many fragments of life from ancient times or organic molecules that once existed on Mars like permafrost on earth. And these lives sealed in frozen soil, even after thousands of years in the ice and snow, can remain lifelike, and may even be waiting for the opportunity of resurrection.

For example, in 2020, in the permafrost of Siberia, the body of a bird 46,000 years ago was found, but it seemed that it had only been dead for a few days. In addition, a mummified frozen cave bear was found, whose history can be traced back to about 39 thousand years ago, and its fleshy black nose and most of its fur were preserved. Not long ago, scientists revived rotifers frozen in ancient Siberian permafrost in the late Pleistocene (2.6 million years ago to 1. 1.70 million years ago). There are also plants that have been re-cultivated for 30 thousand years through immature fruits, and Antarctic moss that has been frozen for 1500 years.

Above: Rotifers.

In short, it is very important to know more about the way and location of water on Mars today, which will help us find a livable environment, possible signs of past life and early organic matter on Mars. Now, the mystery covering Mars is being gradually uncovered by us. When we land on the land of Mars, those ancient memories will eventually appear before our eyes.

# There is a lot of water in the Grand Canyon of Mars #