Just when it feels like we can’t bear the smallness of our earthbound politics any longer, two recent events invite us to look skyward. NASA last week landed a probe on Mars — essentially a high-tech dune buggy with a detachable helicopter — to conduct humanity’s most extensive search yet for echoes of extraterrestrial life there. Meanwhile, a new book by a Harvard astrophysicist suggests we recently glimpsed a different probe, sent by a civilization from another star, as it passed through our solar system.
Admit it: This is more interesting than the latest partisan spitball fight in Washington.
NASA on Thursday afternoon gently set down the six-wheeled rover, Perseverance, within a Martian crater where water once flowed, finishing an almost seven-month, 300 million-mile journey to a target area about the size of downtown St. Louis. The most sophisticated probe ever sent to Mars, it will search for signs of past microbial life. That this remarkable news was overshadowed in the media all week by grubby congressional intrigue is a testament to just how routine planetary exploration has become to us.
The U.S. and other nations have been flinging ships and probes and rovers around the solar system for more than half a century now, circling planets, leaving footprints on the moon and tire tracks on Mars, plunging probes to their meticulously scheduled doom in the hellscape atmospheres of Jupiter and Saturn. Venus’ searing surface is littered today with the melted husks of almost a dozen probes landed there by the former Soviet Union starting in the 1960s. Decades after the U.S. essentially got bored with walking on the moon, China returned with a rover in 2019 to provide humanity’s first ground-level look at the lunar dark side.
The European Space Agency in 2005 set a probe on Saturn’s moon Titan. Last year, NASA briefly landed a probe on an asteroid. Mars may soon need traffic lights: Almost 50 missions there have been undertaken since the 1960s, by nine different governments or alliances, including the E.U., Japan and India. Right now, the U.S., China and United Arab Emirates all have active probes on or orbiting the red planet.
We’ve strewn space junk all over the solar system — and outside of it, having sent several human-made objects into interstellar space over the years. So is it inconceivable that, in the vastness of the cosmos, some other civilization once sent a probe this way, to be fleetingly glimpsed through a telescope in Hawaii three years ago?
That question — and the bigger one: Are we alone? — is the launchpad for astrophysicist Avi Loeb’s new book, “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth.” Part thesis, part autobiography, part searing indictment of scientific rigor mortis, it’s a great read, whatever your thoughts on E.T.
The background: For a few days in October 2017, astronomers tracked a cigar-shaped, football-field-sized … something … that tumbled around the sun and then headed back out to the void beyond Pluto. Its unusual trajectory indicated it came from outside our solar system, the first known interstellar object that humans have seen here.
That alone made it big scientific news, but there was more. As the object (dubbed ‘Oumuamua, Hawaiian for “Scout”) moved away from the sun, it accelerated in a way that couldn’t be explained by gravitational forces alone. Comets do that as the sun vaporizes their ice, pushing them like a thruster, but ’Oumuamua didn’t display the classic comet’s vapor tail. It was a mystery.
Most scientists say it was an interstellar comet, while explaining its un-comet-like behavior with various natural theories — all of which, Loeb argues, are more problematic and unlikely than his: “I submit that the simplest explanation for these peculiarities,” he writes, “is that the object was created by an intelligent civilization not of this Earth.” He posits that ’Oumuamua is an artificially constructed solar “sail” that was being pushed by the sun’s radiation.
It’s important to note here that Loeb isn’t some pointy-ear-wearing UFO gadfly, but was the longest-serving chair of Harvard’s Department of Astronomy and still teaches there. His scientific colleagues mostly reject his thesis, some of them ridiculing it fiercely. Loeb, in his book, ridicules them back. “To explain ‘Oumuamua’s trajectory and retain the assumption that it was a comet,” he writes, “scientists have strained to the breaking point their theories about its physical size and composition.” This is how astrophysicists trash-talk each other.
I’m not by any stretch sold on Loeb’s theory, and I know the cratered ground I’m treading by saying that. One of the strongest pushbacks I’ve ever gotten from readers was in response to a column I wrote two years ago expressing my skepticism about extraterrestrials — not doubting they exist, but questioning how, logistically, they could possibly visit us. The UFO crowd all but threatened to throw me out of an airlock.
But with billions of Earth-like planets in our galaxy alone, it’s almost a mathematical certainty that other life is out there, and perhaps not just the microscopic kind that NASA is seeking on Mars. Loeb vividly expresses his frustration that the search for extraterrestrial intelligence is nonetheless considered exotic among most astronomers — this as they obsess over navel-gazing theories about multiple universes and other groupthink that’s unlikely to ever matter to real people in the real world. Sounds kind of like our politics.