So far, the only planet that scientists have found suitable for life is earth. Even now science and technology have enabled us to find 3976 exoplanets, but they are too far away from the earth.
At present, it is impossible to observe them directly by astronomical telescopes alone, and it is still impossible to determine which exoplanets are habitable planets with life.
Life exists on the earth because it has the basic conditions for life: temperature, water and suitable atmosphere.
So after a very long process of evolution, inorganic matter evolved into organic matter, from low life to high life, until the emergence of human beings.
The earth’s atmosphere contains 78.1% nitrogen, 20.9% oxygen, 0.93% hydrogen, a small amount of carbon dioxide, rare gases and water vapor.
They provide the necessary air for the growth of organisms on the earth. Organisms inhale oxygen and exhale carbon dioxide through respiration, while organisms with photosynthesis inhale carbon dioxide and exhale oxygen.
Respiration and photosynthesis are absorbing each other’s metabolic wastes to keep a balance.
Although other planets also have atmospheres, the composition and content of their atmospheres cannot be compared with that of the earth.
For example, the atmosphere of Venus is extremely dense, mainly composed of carbon dioxide and a small amount of nitrogen; the atmosphere of Mars is very thin, with carbon dioxide accounting for 96%, and the rest is argon, nitrogen, trace oxygen and water vapor.
Although scientists have not yet found that earth like planets are suitable for life on earth, they have found another big event.
Recently, the British journal Nature astronomy published a paper on planetary science, which mentioned that the MIT team found that microorganisms can survive and grow in 100% hydrogen atmosphere.
This discovery is no doubt not to tell us that exoplanets whose atmospheres are mainly composed of hydrogen have life, and these life may be rich and diverse.
In the universe, the atmosphere rich in hydrogen is more and better than the earth like planets rich in oxygen, such as Jupiter, which is relatively close to us.
And k2-18b, which is 124 light-years away from the earth, is known as the super earth by scientists. Its atmosphere is mainly composed of hydrogen.
Sarah Seg, a planetary scientist at MIT, and his colleagues conducted growth experiments in the laboratory using Escherichia coli (representing prokaryotes) and yeast (representing eukaryotes).
They exposed cultured E. coli and yeast to 100% hydrogen. To their surprise, E. coli and yeast performed very well. Although their reproduction speed was slower than that in the air, they could also reproduce normally.
For E. coli, the reproductive efficiency is about half as low as for yeast, which is about 2.5 times lower.
Although the growth is slow due to lack of oxygen, it is also in the growth state.
Because for the earth’s microbes, they can withstand high and low temperatures, grow in the upper atmosphere, or live on rocks half a mile below the bottom of the sea.
And this experiment found that they can even survive and reproduce in 100% hydrogen. What a shocking discovery!
In the harsh environment of space, life can be born and exist, so it will be easier to find extraterrestrial life.
Xiaobian believes that this discovery provides new ideas and means for scientists to explore exoplanets and find life. It makes us break the original understanding and rise to a new stage.
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