When scientists used high-powered telescopes to stare deep into space looking for exoplanets, they found that the world was always interesting for a variety of reasons. Planets that are closest to Earth in size and composition are the most exciting, because rocky planets like Earth offer the best chance of discovering life. Planets in habitable zones around stars are more exciting because they may have liquid water on their surfaces. Researchers believe that water is the key to life, and that oxygen is clearly a big supplement. But for a world rich in hydrogen, it is often considered unfriendly to life on Earth.
In a new paper published in the journal Nature-Astronomy, a team of scientists suggests that not only can a world with high levels of hydrogen support the existence of life, but that life may actually thrive on such planets. The researchers built their optimism on experiments that showed that yeast and E. coli not only survive in an atmosphere containing 100 percent hydrogen, but also reproduce.
Hydrogen is not abundant on Earth. However, many other rocky worlds are the opposite. Astronomers know this because light hydrogen in the planet’s atmosphere causes a larger “bubble” around it. This makes hydrogen-rich planets easy to spot, but it doesn’t necessarily tell us if there’s life there.
“We have shown that single-celled microorganisms that do not normally live in an H2-based environment can survive and grow in 100% of the H2 atmosphere,” the researchers wrote. “We also described the amazing diversity of dozens of different gases produced by E. coli, including many that have been proposed as potentially biometric gases. This work demonstrates the practicality of the experiment, which can better determine which extraterrestrial environment can carry some form of potentially detectable life. “