Written by Farhad Manjoo
The sun is not special. I know that’s a churlish thing to say about our planet’s eternal clock, giver of light, life and spectacular Instagram backdrops. Awesome as it is, though, the sun is still a pretty ordinary star, one of an estimated 100 billion to 400 billion in the Milky Way galaxy alone.
Then there is Earth, a lovely place to raise a species but, as planets go, perhaps as unusual as a Starbucks in a strip mall. Billions of the Milky Way’s stars could be orbited by planets with similarly ideal conditions to support life.
So isn’t it hubris to assume that we’re the only life around? Since Nicolaus Copernicus posited nearly 500 years ago that Earth is not at the centre of the universe, much of what humanity has learned about the cosmos has confirmed our insignificant ordinariness. In all the vastness of space and time, then, doesn’t it seem likely that there exist other ordinary beings…?
You might respond with physicist Enrico Fermi’s famous paradox: If life is so common, why haven’t we seen it?
Now, in a dazzling new book, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, astrophysicist Avi Loeb offers a rejoinder to Fermi. Loeb, a professor at Harvard, argues that the absence of evidence regarding life elsewhere is not evidence of its absence. What if the reason we haven’t come across life beyond Earth is the same reason I can never find my keys when I’m in a hurry — not because they don’t exist but because I did a slapdash job looking for them?
“The search for extraterrestrial life has never been more than an oddity to vast majority of scientists,” Loeb writes. To “them, it is a subject worthy of, at best, glancing interest and at worst, outright derision.”
That attitude may be changing. In the past few years there has been a flurry of new interest in the search for aliens.
Still, Loeb argues, we are not looking hard enough. Other areas of physics are showered with funding and academic respect, while one of the most profound questions humanity has ever pondered — Are we alone? — lingers largely on the sidelines.
Loeb is a former chair of Harvard’s Department of Astronomy. He has spent much of his career studying the early universe and black holes, but in the past few years he has become best known for his eccentric analysis of a cosmic mystery that unfolded over 11 days in 2017.
That October, a telescope in Maui captured an exotic speck speeding across the sky. It was interstellar — recognised as the first object we’ve ever seen that originated outside our solar system. Unusual though it was, the astronomical community quickly arrived at a consensus: The object — named Oumuamua — was some kind of comet, asteroid or other body of natural origin.
What accounts for the reflexive skepticism? Much of it is a matter of optics — looking for alien life just sounds kind of zany. In 1992, NASA spent $12 million on a project to listen for radio signals from other planets; the next year, Congress cut the funding, with one senator joking that “we have yet to bag a single little green fellow.” For almost three decades after the funding, there was essentially no NASA support for the search for extraterrestrial life.
The drought finally ended last year, when the space agency funded an effort by Loeb and several colleagues to look for “technosignatures” of life on other planets — for instance, the presence of industrial pollutants or a concentration of bright light similar to what we see in our densest cities.
Besides a lack of resources, Loeb says the search for aliens has been hampered by risk aversion and groupthink. Young scientists rarely push boundaries because doing so risks making mistakes, and mistakes don’t advance careers.
That attitude feeds on itself, fostering sameness and insularity. Loeb points out that many of the most fashionable research topics in physics lack much experimental backing. But there is compelling evidence to suspect that life exists elsewhere.
There is much we could do to keep an eye out for beings elsewhere — at the least, as Loeb suggests, surrounding the planet with a network of orbiting high-definition cameras so that the next time an Oumuamua-like object comes hurtling by, we can get a closer glimpse of it. He calls for allocating more scientific resources, like access to telescopes, to high-risk projects. He proposes the creation of a cross-disciplinary science, “astro-archeology”, dedicated to detecting and analysing relics in other worlds.