Can life on an oxygen-free exoplanet survive? Earth bacteria can do it.

Beijing time on May 19, according tomedia reports, in the exoplanet, there is breathing helium and hydrogen extraterrestrial life? A new study of life on Earth suggests that this is possible, which means that we may need to change our minds as we search for life in the universe. We need to focus not only on planets that may be filled with oxygen, but also on planets whose atmospheric composition seems unsuitable for life.

Can life on an oxygen-free exoplanet survive? Earth bacteria can do it.


There is no doubt that oxygen is good for the survival of life, after all, this is the gas on which we live on earth. But oxygen is not common in the universe, accounting for only 0.1% of the mass of the universe. More common in the universe are hydrogen (92%) and helium (7%). Jupiter, the largest planet in the solar system, has a large atmosphere filled with hydrogen and helium, with only a few other elements. Rocky planets like Earth, which lack hydrogen and helium in the atmosphere, make up only a small part of the star system.

With hydrogen and helium in the universe dominating, it makes sense to know whether the atmosphere, which consists of these elements, can support life. The team, led by Sarah Siegel, a planetary scientist at the Massachusetts Institute of Technology, is trying to find out. They chose two earth creatures that could survive in oxygen-free conditions: E. coli, a bacterium found in the intestines of many animals, including humans; and common yeast, a fungus used to bake bread and brew beer.

The researchers placed the living mediums of the two creatures in several different flasks and replaced the normal air with other gases. One set of flasks was filled with pure hydrogen, the other was filled with pure helium, and the third set of flasks was filled with normal air.

Every few hours, the researchers took out some E. coli and yeast to determine if they survived. Both microbes can survive in different gases, the report said, and are best in the air. This is not surprising, given that both have evolved on Earth. E. coli grows twice as fast in air-filled flasks as normal, while yeast grows 2.5 orders of magnitude less.

However, the fact that both creatures could survive in pure hydrogen and helium environments was an important inspiration for astrobiologists, and the discovery “opens up the possibility of finding a wider range of habitats for life on different habitable planets.” E. coli also produces a range of metabolic wastes that may include ammonia, methanol and nitrous oxide as biological features of the possibility of extraterrestrial life.

The question, then, becomes how this new study will advance our exploration of life on other planets. For a long time, the field of astrobiology was considered a speculative one. In this field, scientists will consider the possibilities, but there is no data to constrain their thinking. After all, we have never observed life on other planets. It was only in recent decades that astronomers confirmed the existence of planets orbiting other stars outside the solar system.

In the early days of exploring exoplanets, astronomers found only Jupiter-like gas giants, which are very close to the host star, known as “hot Jupiter.” For a while, these hot Jupiters seemed to be the most common type of exoplanet, but this was actually misleading. The discovery of these gas giant planets is mainly due to their gravitational pull as they orbit, causing the parent star to oscillate, which astronomers can observe. Large planets orbiting in narrower orbits can cause larger swings that make them easier to detect.

That changed again in 2009, when the Kepler Space Telescope was launched. The Kepler Space Telescope uses a new method to find exoplanets. Simply put, when looking at distant stars, the Kepler telescope looks for shadows cast as the planet passes in front of its parent star. The Kepler telescope ceased to function at the end of 2018, but over a decade it has discovered more than 2,600 exoplanets. The characteristics of these planets vary, and many of them are hot Jupiters.

However, the Kepler space telescope cannot find life on these planets. First, many of the planets it found were so far away from Earth that it was difficult to capture their atmospheres; Now, the first problem is being solved by the Ling-Sun Exoplanet Survey Satellite (TESS). Launched in early 2018, the satellite uses the same technology as the Kepler telescope to survey nearby stars and look for Earth-like planets.

Looking at the atmosphere sofe of exoplanets requires more powerful telescopes than kepler or TESS. Astronomers first observed the atmosphere of exoplanets in 2001. Using the Hubble Space Telescope, the researchers looked at a star called HD 20945. As a planet passes in front of the star, Hubble’s instruments observe the light released by sodium. Astronomers explain that this is sodium suspended in the planet’s atmosphere. Another study in 2008 also revealed that the planet was surrounded by hydrogen.

Of course, that’s why a recent study by the Massachusetts Institute of Technology is so interesting. Astronomers already know that Jupiter’s atmosphere is made up mainly of hydrogen and helium, and they have observed a hydrogen-filled atmosphere around a planet orbiting distant stars. Based on the new findings, astrobiologists should perform spectral analysis of hydrogen-encrusted planets and keep a close eye on rocky planets with such atmospheres, the researchers said.

For everyone interested in the life of an alien star, the future is full of hope. The TESS Observatory is busy searching for nearby exoplanets, and the much-anticipated James Webb Space Telescope (JWST) will launch in 2021, according to NASA. The telescope is designed to replace the much-successful Hubble telescope. Astronomers hope to use JWST to scan known exoplanets for signs of life. Now, astrobiologists are sure to add planets surrounded by hydrogen to their list of explorations.