“For nearly 70 years the scheme favored by most scientists has been to look for signals — radio transmissions,” says SETI scientist Seth Shostak. “That’s the classic approach of SETI (the search for extraterrestrial intelligence), and frankly, it makes sense. Radio can easily traverse light-years, and the technology for detecting it is well known and highly sensitive. But is looking for signals really the best plan? Is it possible that we’re making the wrong bet?”
The alternative is to search for alien objects –that an advanced society has constructed somewhere in space but so far, humans have failed to detect any signs of engineering beyond Earth –zero alien megastructures or Dyson spheres.
In November of 2018, we reported that you would have though it was 1938 again following Orson Welles’ radio broadcast of the War of the Worlds the way the way Twitter lit up when the chairman of Harvard’s astronomy department, Israel-born theoretical physicist Avi Loeb, suggested that an alien spaceship was possibly on its way to Earth to study humankind, and probably had Stephen Hawking spinning in his grave.
Back in October, Loeb published a study explaining how aliens can travel throughout the galaxy on the backs of everything from meteoroids to space dust. “Our paper considers the possibility that life could be transported across the entire Milky Way galaxy and beyond,” Loeb said. “The solar system acts as a gravitational ‘fishing net’ that contains thousands of bound interstellar objects of this size at any given time. These bound interstellar objects could potentially plant life from another planetary system and in the solar system.”
All hell broke loose last when Loeb followed up with a new paper suggesting that the interstellar object we know as Oumuamua might be a spaceship, “a lightsail, from an alien civilization.”
Loeb has spent much of his amazing career searching for alien life. In addition to his myriad Harvard hats (Director of Harvard’s Black Hole Initiative and Director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics), he’s the chair of the Breakthrough Starshot Advisory Committee, a $100 million initiative that is currently listening for signs of aliens.
To refresh your memory on the backstory: about a year ago, scientists using some of the biggest telescopes on earth detected an odd oblong-shaped mystery object floating through space. They said the interstellar asteroid is like nothing that’s been seen in the solar system before, with an “extreme oblong shape” that’s as much as 10 times as long as it is wide. ‘Oumuamua was discovered Oct. 19 using the Pan-STARRS telescope, which is operated near the summit of Maui’s Haleakala volcano by the Institute for Astronomy at the University of Hawaii.
The dim object was spotted as it traveled through the inner solar system, at a distance of about 19 million miles from Earth, but an analysis of its trajectory suggests that it came in from a place far beyond the solar system, somewhere in the constellation Lyra, heading towards the constellation Pegasus.
Named Oumuamua, Hawaiian for “Messenger from Afar”, it’s believed to be the first interstellar object observed passing through our solar system. Many tried listening to it, to see if they could determine what it was. Was it a shard from an ancient asteroid, a weird comet? Or was it something else?
Pinging Seth Shostak
So we emailed SETI’s world-renowned senior astronomer, author, and alien hunter, Seth Shostak. Here’s what we asked him…
“We’d like to include a quote (of any length) from you on your thoughts about human implications of the Oumuamua “spacecraft” debate. In short, it seems that we are rooting beyond the science for validation of the spacecraft hypothesis. In the rancorous, tribal environment we’re living through, it appears the human species is yearning for validation of intelligent life beyond our fragile Blue Dot.”
It’s true that the Harvard paper suggesting that this object might be engineered, rather than simply the ten millionth rock from the Sun, has certainly provoked a lot of interest by the public. But one should keep in mind that the idea of alien company has perennially been interesting to the public. Personally, I think that’s because we’re hard-wired to be curious about potential competitors or – if you’re into the abduction mind set – mates. We all like the idea of aliens, and that’s not just because they’re frequent bit players on TV and in the movies (indeed, they get these roles because we ARE interested in extraterrestrials, not the other way ‘round.)
This has been true for as long as I’ve been paying attention: Any claim of alien activity has stirred interest. Much of this is kind of non-scientific – the UFO phenomenon, for example, relies a lot on witness testimony or ambiguous photographic evidence, but never fails to make the news. One-third of the public seems to think that we really are being visited by extraterrestrial tourists. That’s been true for many decades, and I think that the Oumuamua story is in some sense similar. We wish to believe that Homo sapiens is interesting and significant enough to warrant visitors from some other world. Obviously, that’s kind of self-centered (I wonder if dinosaurs made reports of alien craft come to Earth to abduct them!) But while the anthropocentrism is certainly mildly amusing, it’s also thoroughly understandable. As the self-proclaimed “crown of creation,” humans naturally would like to think that the rest of the cosmos is keen to know more about us – that we’re still, in some sense, at the center of the universe, despite Copernicus’ best efforts. It’s obviously far less interesting to suggest that Oumuamua might be no more than an insensible, random hunk of ice.
A New Idea for Searching for Alien Artifacts
University of Chicago physicist Daniel Hooper has offered a new if far-fetched idea for searching for high-tech alien artifacts. Here’s his argument: the universe is expanding, and galaxies are growing ever farther apart. So forward-thinking alien societies might want to grab stars from nearby galaxies while they can and park them in their cosmic neighborhoods as insurance against future energy depletion. If collections of corralled stars do exist, they’d be easy to spot in the course of mainstream astronomy research.
“Yes, efforts to find Dyson spheres have come up empty,” says Shostak. “And we haven’t found any stellar stockpiles either. But tomorrow could be different.”