Professor Ling, a senior bioengineer, believes that even if there are organisms on planets outside the Earth, the environment in which these organisms live is not necessarily similar to that of the Earth. For example, there are some extreme environments on the earth, and in our common sense, there will be no living creatures in these places, but in fact, people have found a lot www.biquge.info of living things in these extreme environments. Therefore, there may be living organisms even on celestial bodies that are different from the Earth's environment. What is life in extreme environments?

1。 Hydrothermal: Life in boiling water. Can you imagine life in boiling hot water? Common proteins, such as eggs, meat, etc., lose their vitality within a few minutes at 100'C. The hot springs in Yellowstone National Park in the United States, with water temperatures close to 100'C and some places as high as 300'C, still have a lot of life to live freely and freely. These life forms include various algae, bacteria, archaea, etc. The study found that these forms of life were most likely the earliest forms of life on Earth.

2。 Polar: -250'C is not afraid. Polar bears can roam in minus 20'C environments, which is not something that ordinary animals can try. Compared to the psychrophilic bacteria that survive in minus 250'C, polar bears are not very cold-tolerant. Outside of the Earth, ultra-low temperature environments such as Uranus and Neptune are very common, and the emergence of psychrophilic bacteria has also given people the confidence to discover extraterrestrial life.

3。 Underground: high temperature and high pressure and lack of oxygen. In the 2,000-meter-deep formation, there is almost no air, and some are under extreme conditions of high temperature, high pressure and lack of oxygen, but there are still a large number of acidophilic, iron-loving and methane-loving microorganisms living here, which rely on reduced iron and methane to survive.

In addition, in the dark world where there is no light in the depths of the ocean, in the salt lakes with extremely high salinity, in the air with thin air and strong ultraviolet rays at an altitude of 10,000 meters, and in the comets, passing through the solar system。。。。。。 It has been discovered that life and comet tail dust contain trace amounts of methane and other viruses and cosmic archaeal forms; From this, we can infer that there are some planets other than Earth, where life can exist.

In addition, in 1996, the American "Mars Pathfinder" successfully landed, releasing the first Mars rover "Sojourner", and sent back a large amount of evidence that Mars was once warm and humid and had an atmosphere. In 2004, the European Space Agency's Mars Express detected trace amounts of methane in the Martian atmosphere, providing new evidence for the possible existence of life on Mars. In the same year, "Courage" and "Opportunity" landed on Mars and successfully discovered that although Mars is very cold now, there has been water in history - since the human spacecraft landed at the North Pole of Mars in the middle of the 21st century, NASA has claimed that the water ice permafrost under Mars can extend from the polar region to 60' latitude, and if the ice in the polar crown of the South Pole of Mars melts, it will cover the entire planet up to 11 meters deep.

The Opportunity rover found that there are many small balls like blueberries on the surface of the Martian rocks, all of which are formed by the action of water. These "little blueberries" and other evidence, such as rocks and fault formations near craters, suggest that there was once water flowing on Mars, and even lakes and oceans. At that time, Mercury was perhaps warmer and wetter, more Earth-like. For example, if there was liquid water on Mars before, does this mean that there was life in the past? Many scientists are working tirelessly to find out about this.