"Contentious" book claims Oumuamua was extraterrestrial spacecraft

In his new book Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, theoretical physicist and Harvard professor Avi Loeb (previously at BB) reportedly theorizes about an extraterrestrial spacecraft that may-or-may-not have recently passed by the Earth's orbit.

The incident in question took place in 2017. At the time, NASA dubbed it "Oumuamua" and referred to it as "the first confirmed object from another star to visit our solar system." They went on:

This interstellar interloper appears to be a rocky, cigar-shaped object with a somewhat reddish hue. The object, named 'Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated—perhaps 10 times as long as it is wide. That aspect ratio is greater than that of any asteroid or comet observed in our solar system to date. While its elongated shape is quite surprising, and unlike objects seen in our solar system, it may provide new clues into how other solar systems formed.

The observations suggest this unusual object had been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with our star system.

Given the object's bizarre cigar-like shape, Loeb insists in his book that, "This would make 'Oumuamua's geometry more extreme by at least a few times in aspect ratio — or its width to its height — than the most extreme asteroids or comets that we have ever seen."

He adds: "The only way to look for [alien civilizations] is to look for their trash, like investigative journalists who look through celebrities' trash." Which is probably why Publisher's Weekly refers to the book as a "contentious manifesto."

Loeb expounded on these ideas in a recent article for Scientific American:

As a regular comet, `Oumuamua would have had to lose about a tenth of its mass in order to experience the excess push by the rocket effect. Instead, `Oumuamua showed no carbon-based molecules along its trail, nor jitter or change in its spin period—as expected from cometary jets. The excess force could be explained if `Oumuamua was pushed by the pressure of sunlight; that is, if it is an artificially-made lightsail—a thin relic of the promising technology for space exploration that was proposed as early as 1924 by Friedrich Zander and is currently being developed by our civilization. This possibility would imply that `Oumuamua could be a message in a bottle.


Perhaps `Oumuamua represents our first encounter with a plastic bottle, manufactured by an advanced technological civilization. Lightsails can be designed to weigh a gram per tens of meters squared of surface area, comparable to the area of `Oumuamua.

If you want to know more, here's the full blurb for Loeb's new book:

In late 2017, scientists at a Hawaiian observatory glimpsed an object soaring through our inner solar system, moving so quickly that it could only have come from another star. Avi Loeb, Harvard's top astronomer, showed it was not an asteroid; it was moving too fast along a strange orbit, and left no trail of gas or debris in its wake. There was only one conceivable explanation: the object was a piece of advanced technology created by a distant alien civilization.
In Extraterrestrial, Loeb takes readers inside the thrilling story of the first interstellar visitor to be spotted in our solar system. He outlines his controversial theory and its profound implications: for science, for religion, and for the future of our species and our planet. A mind-bending journey through the furthest reaches of science, space-time, and the human imagination, Extraterrestrial challenges readers to aim for the stars—and to think critically about what's out there, no matter how strange it seems.

Also worth noting: While Loeb is an American citizen who was born in Israel, he should not be confused with Haim Eshed, the retired Israeli military officer who also recently spoke out about aliens.

Extraterrestrial: The First Sign of Intelligent Life Beyond Earth [Avi Loeb]

Let's Search for Alien Probes, Not Just Alien Signals [Avi Loeb / Scientific American]

A Harvard professor has claimed in his new book that alien debris passed near Earth in 2017. It has attracted both skepticism and intrigue. [Kevin Shalvey / Business Insider]

IMAGE: Joe Wos / Wikimedia Commons (CC-BY-SA 4.0)