Enrico Fermi’s much ballyhooed paradox — the aging saw that “If E.T. is out there and technologically-advanced, why aren’t they here?” — now seems a tad simplistic.
It’s a conundrum that has plagued SETI (Search for Extraterrestrial Intelligence) researchers since their first radio searches began more than a half century ago. But the lack of verifiable SETI signals should not be held up as evidence that they simply aren’t there.
In this age of planetary plenty, when by some estimates there may be as many as 100 billion planets in our galaxy alone, it’s still premature to think that we have cornered the Milky Way’s market on intelligence.
That’s not to say that anyone need keep one eye open for bug-eyed aliens skulking about the foot of one’s bed. But if technologically-advanced extraterrestrials are out there, there is ample reason to believe that they will have long known we’re here.
Here are five reasons why:
1) The “I Love Lucy” Argument.
Even if E.T. has only crude 1960’s-era radio telescopes, they would be able to pick up 1950s-era TV broadcasts out to a distance of at least 60-plus light years. Given the recent announcement that one of the stars in the Alpha Centauri star system, our nearest stellar neighbors, has an earth-sized planet, the implication is that there may be dozens of terrestrial mass within only a hundred light years.
2) “Earth, you’ve got to hide your life away…”
Putting a new spin on that old Beatles tune, our own planet’s numerous bio-signatures due to both plant photosynthesis and animal respiration would be readily apparent to extraterrestrial astronomers.
Before funding cuts put a squelch on plans for NASA’s Terrestrial Planet Finder (TPF) and Life Finder (LF) spacecraft, the space agency was already well along in its plans to sniff out signs of life on dozens of nearby extrasolar planets.
As I note in my book “Distant Wanderers,” French astronomer Antoine Labeyrie, says that within a century at the outside, large-scale ground- and space-based optical arrays will be used to track real time weather on other nearby earthlike planets.
Thus, if within fifty years of Sputnik, we are capable of using space-based spectroscopy to sniff out life on other earthlike worlds; then an Alien Search for Terrestrial Intelligence (ASTI) must possess capabilities a thousand fold in advance of our own. That is, if they are even a modest 10,000 years ahead of us.
A 2007 paper published by The Astrophysical Journal notes that with an array of large very powerful optical space telescopes, “hypothetical observers” would likely be able to establish earth’s rotation period, discern its oceans, and possibly even its signatures of life — all from data contained in a single pixel and from an
estimated distance of 30 light years.
3) They aren’t likely to be couch potatoes.
Arguments against extraterrestrials out riding the spacetime continuum are flawed. From Christopher Columbus, who barely squelched a mutinous crew — to the Apollo 11 lunar module crew narrowly avoiding an unexpected crater just before touchdown; great leaps have always been made running on empty. Why should we expect an advanced intelligence to be couch potatoes, content never to push the envelope across their own heliopause?