In an essay originally published in Griffith Review, 3D-bioprinting researcher Cathal O’Donnell wrote that “Discovery [of alien life] now seems inevitable and possibly imminent” following groundbreaking discoveries over the past twenty years.
While life may seem like a mystical phenomenon, O’Donnell writes, it is actually a “special kind of complex chemistry” involving some of the universe’s most common elements: carbon, hydrogen, and oxygen. Amino acids like the ones that comprise every protein in human bodies are present in the tails of comets. Soil on Mars contains numerous organic compounds.
University of California, Berkeley researchers calculated that there nearly 40 billion Earth-sized exoplanets located at distances from their respective stars where temperatures allow for the existence of liquid surface water.
Moreover, life on Earth formed soon after the planet itself was created.
O’Donnell writes, “The oldest fossils ever found here are 3.5 billion years old, while clues in our DNA suggest life could have started as far back as 4 billion years ago, just when giant asteroids stopped crashing into the surface.”
And living creatures exist on our planet in places that we would never think possible. Organisms make homes out of lakes of sulphuric acid, inside storage sites of concentrated nuclear waste, and in rocks buried 3 miles below the Earth’s surface.