Can life on Earth survive on other planets? Scientists' discovery may surprise you.

Astronomers have discovered numerous planets with extreme conditions where life, as we know it, is impossible. However, within our galaxy, there are rocky planets roughly the size of Earth that reside in the habitable zones of their stars. If a planet is at the right distance from its star to have liquid water on its surface, it is considered to be in the habitable zone. A new study published on the preprint server arXiv highlights the crucial role of a planet's atmosphere in determining how suitable that world may be for life. Can microbial life from Earth survive on some Earth-like planets? This is discussed by Phys.

Scientists believe that not only the presence of liquid water on the surface of a rocky planet but also its atmosphere plays a significant role in how habitable the planet is. A dense atmosphere on a planet, even one located beyond the habitable zone, may help maintain liquid water on the surface. Researchers state that simply having liquid water does not guarantee the presence of life.

The scientists created models of Earth-like planets with varying atmospheric compositions. They then investigated whether Earth microbes could survive under these conditions through laboratory experiments. In some cases, the atmospheric composition was similar to that of Earth, while in other simulations, the planet's atmosphere consisted largely of carbon dioxide, nitrogen, methane, and hydrogen. According to the researchers, the modeling took into account that water is a variable component that can disappear due to pressure or temperature.

The results of the laboratory experiments showed that the composition of a planet's atmosphere significantly influences bacterial growth patterns, underscoring the importance of studying the atmosphere when assessing the habitability of an Earth-like planet.

Surprisingly, Earth bacteria thrived well under various atmospheric compositions. Although there was some delay in their growth as the bacteria adapted to the new conditions. This means that microbial life could survive on a planet that not only has typical Earth air but is also rich in nitrogen, hydrogen, or methane. The most challenging environment for bacteria to survive is one dominated by carbon dioxide, although after some adaptation, they manage to thrive, the scientists say.

The authors of the study suggest that rocky planets the size of Earth, with atmospheres rich in hydrogen, methane, and nitrogen, may still support microbial life. If these planets had time to adapt to unusual conditions, Earth bacteria could prosper there. This means that if life similar to that on Earth exists somewhere in our galaxy, it could be discovered since it might thrive in entirely different conditions. At least theoretically, this is possible.

The research also indicated that planets with dense atmospheres rich in hydrogen could have liquid water on their surfaces, even if they lie beyond the habitable zones of their stars.