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Detecting Extraterrestrial Life Using Small Tools
Microbes are incredibly diverse. Bacteria were among the first life forms on Earth almost four billion years ago. They're in the ocean deep, boiling hot springs, gold mines, the Antarctic, and miles above in Earth's atmosphere, even on the International Space Station.
We may have identified less than point zero one percent of all bacterial species on Earth, so there's still an infinite amount to learn. We know they're earth's best recyclers because they can grow on and degrade nearly everything even Styrofoam!
That's why scientists are using them to test for the existence of extraterrestrial life on Mars and rocky planets orbiting distant stars. In a recent study, E. coli was able to grow in an atmosphere made of one hundred percent hydrogen or helium gas. And as they grew, they produced gases such as nitrous oxide, ammonia and methanethiol.
It's likely alien microbes could also grow in atmospheres with these gases. So using studies like these, astronomers could potentially detect these gases on distant planets by analyzing light passing through its gaseous atmosphere. They could analyze the light using the future James Webb orbiting telescope which will replace the Hubble Space Telescope. Snce they do, they could potentially identify not only possible but specific types of life there assuming water is also present.
Just as ET phoned home in the eighties blockbuster film, maybe we can do the same by dialing into the chemical biosignatures emanating from far off planets.
More Information
Planets with hydrogen-rich atmospheres could harbor life
Lab experiments show that yeast and E. coli survive and reproduce in hydrogen-rich conditions...
Laboratory studies on the viability of life in H2-dominated exoplanet atmospheres
Theory and observation for the search for life on exoplanets via atmospheric 'biosignature gases' is accelerating, motivated by the capabilities of the next generation of space- and ground-based telescopes...
Laboratory studies on the viability of life in H2-dominated exoplanet atmospheres
There are several ideas of how rocky exoplanets (small planets with radii smaller than about 1.7 Earth radii) may have formed and maintained H2-dominated atmospheres. Rocky exoplanets release H2 gas to their atmospheres as water reacts with metallic Fe in accreting materials during planet formation...
