It used to be that we meager humans had no idea how many plants might be out there beyond our own adorable little solar system. Today, we know there are more planets than stars in our galaxy. That’s hundreds and hundreds of billions of planets.
Jill Tarter of SETI is really excited about this. I am too.
There are two big discoveries of modern science that have raised her hopes for the existence and discovery of life beyond Earth: the existence of extremophiles on our planet, organisms that can survive and thrive in the most hostile conditions our planet can muster; and of course the discovery of all these exoplanets.
These two factors combined suggest that “the universe might be bio-friendly.” Might! If we do find life on another planet or moon, either in our own solar system (with one big exception) or from an exoplanet, “that will mean life is ubiquitous everywhere.”
Why? Because a “genesis moment” somewhere more or less quarantined from Earth would mean that life has the potential to emerge throughout the universe. The exception I mentioned is Mars, which shares too much of a history of “exchanging rocks” with Earth and Venus to make it definitive as to which planet life began on.
That’s also a big deal! It’s entirely plausible that Mars is where our own life began, with Mars seeding Earth with the beginnings of our life. “So, indeed, we could be Martians.”
Intelligent life is an entirely different level of difficulty, of course. But while it may be too hard to detect a biosignature from an exoplanet (which Tarter admits we don’t even have for Earth life), we could detect evidence of a civilization’s technology: “That could be more distinct and distinguishable.”
Okay, so why does this matter, beyond being “cool”?
“One of the best things about SETI is the fact that you have to adopt a much more cosmic perspective,” said Tarter. “It’s like holding up a mirror to the entire planet and saying, See? See you guys? You’re all the same, when comparing yourself to something else that co-evolved on a different planet.”
SETI, she says, “trivializes the differences between us” so we can “grow up” and develop some kind of global scheme for cooperating. But for that, we have to work together. And not just within our own species. All life forms on Earth have to be included in our thinking and in our coming interstellar moral circle.