Japanese scientists have found that abnormal cocci can survive in harsh space environment for up to eight years

In 2018, a spacecraft leaves the international space station with an unusual cargo: bacteria that have spent years in space. These microbes are the final samples returned to earth as part of the tanopo mission, a Japanese astrobiology experiment to study the effects of space environment on simple organisms. If microbes survive long-term exposure to vacuum, this will give a major boost to the controversial theory called “biogenic theory,” which suggests that life flies between planets between asteroids, comets and space dust. < / P > < p > on Wednesday, a new study by the Tanpopo team was published in the, which details how a variety of abnormal cocci survived three years of exposure to harsh space conditions. Known for its extraordinary resistance to genetic damage caused by high doses of ultraviolet radiation, the bacterium classifies it as other so-called “extreme microbes,” such as retarders. But the researchers are not sure how the feat was achieved. “Anococci have a variety of mechanisms for survival in harsh environments,” said Akihiko Yama, a professor at Tokyo University in Japan and chief scientist of the tanopo mission “We tested the responsible mechanism of the bacterium and found that its DNA repair system is very important for its survival in the space environment.” < / P > < p > as part of the tankopo experiment, Akihiko Yama and his colleagues exposed dry colonies of three different species of the genus anococci to a space vacuum in an experimental module outside the space station. When the researchers replenished the colonies on earth, they found that their outermost layer died from exposure to high doses of ultraviolet radiation. But the dead layer of bacteria protects the DNA of the microbes below from damage. No matter how thick the colony is, the number of complete bacterial genes decreases from exposure to space. The team’s results show that only a half millimeter deep bacterial mass can survive in space for up to eight years. This is good news for those who support the theory of biogenesis, which dates back to the early 1970s and shows that life was sown by microbes on fast-moving space rocks. This is far from the mainstream view, but one of its earliest supporters, mathematician Chandra viklamasingh, believes it can explain some of the thorny problems of life on earth. A typical explanation is that life is formed by the collision of a group of organic molecules in the boiling original mud, and gradually form more complex molecules. Eventually, these molecules combine to form unicellular organisms, such as bacteria, and then evolve into multicellular organisms, and so on. But, as far as scientists know, life on earth is smooth. The peak of speciation is very short, but the stagnation period is long. About four billion years ago, bacteria appeared, and they became the main life form on earth in two billion years. Then there was the explosion of slightly more complex single celled organisms, and eukaryotes ruled for another billion years before more complex creatures finally began to emerge. < / P > < p > these long-term evolutionary pauses are puzzling. One explanation is that these equilibrium periods are caused by extinction events, which create new opportunities for speciation. Those who believe in biogenesis believe that if wayward extraterrestrial microbes push early life forward, it can explain the unusual evolutionary timetable on earth. According to the theory of biogenic origin, asteroids and meteorites that impact on the earth may contain some basic organisms or genetic materials, which have changed the evolutionary trajectory of life on earth. The number of bacteria that arrive at an asteroid is unlikely to change the evolution of the entire planet. If bioaccumulated space rocks are common in this part of the galaxy, they believe, the heavy bombardment earth experienced four billion years ago may be enough to solve the problem. This is a big hypothesis, but there is some evidence to support it. Harvard physicist avi Loeb said: “when protected deep in rock, calculations show that bacteria can survive millions of years.” The simulation of < / P > < p > has shown that this process can go another way. If life had begun billions of years ago when it was smashed by an asteroid, some of those terrestrial microbes might have exploded from the surface and ended up on another planet in the solar system. This may sound far fetched, but researchers have found rocks from Mars on earth, so there is good reason to suspect that we will one day find earth rocks on Mars, Loeb said. < / P > < p > therefore, if NASA finds evidence of life on Mars and rocks on Mars, life on Mars may also come from earth. Indeed, if scientists find life on Mars, one of the biggest challenges will be to determine its origin. But there are also clues, for example, that all DNA on earth spirals in the same direction. If DNA is found to be spinning in the opposite direction on Mars, there is ample evidence that life originated independently from the red planet and that life did not fly from earth to Mars. Even if you don’t believe the biogenic hypothesis, the tanopo team’s results have a serious impact on planetary conservation, Loeb said. NASA and other space agencies have a lot of trouble making sure that the spacecraft, when launched to Mars, will not carry any biomaterials from earth. They don’t want to accidentally destroy the original environment, where they are looking for faint signs of ancient alien life. But now, Akihiko Yamaguchi and his team in Japan have shown that certain types of bacteria can survive long enough in deep space to travel without any protection. < / P > < p > “any millimeter thick aggregates in the cleanroom will be cleaned and erased before the Mars mission.” “But these results make us aware of the importance of sterilizing all spacecraft sent to other planets in search of life,” Loeb said < p > < p > in 2018, akihihiko Yama and his colleagues conducted a series of high-altitude experiments on the earth using airplanes and weather balloons, and found traces of abnormal coccal bacteria in the atmosphere nearly 11 kilometers. This is much higher than the cruising altitude of the airliner. But that doesn’t mean the earth is leaking these strong microbes into space. Small microbial communities floating in the breeze cannot escape the effect of gravity. But as Loeb detailed in a paper he co authored earlier this year, asteroids and comets could sweep through the earth’s atmosphere like rocks in a pond, absorbing some of the microbes in the atmosphere and bringing them into interstellar space. There are still controversies about the theory of the origin of students, and it has not been widely accepted in the scientific community. But for now, experiments like Tanpopo are still challenging our assumptions about the conditions necessary for life. 865 optimization is different? These mobile phones should teach you a lesson!

Author: zmhuaxia