“I don’t see extraterrestrials as more speculative than dark matter or extra dimensions,” says Harvard’s Avi Loeb, who has spent much of his extraordinary career searching for alien life. “I think it’s the other way around.”
Solar System Acts as a Gravitational Fishing Net
“Only a fraction of the interstellar objects might be technological debris of alien civilizations,” said Loeb after Twitter lit up in November of 2018 when the chairman of Harvard’s astronomy department, Israel-born theoretical physicist suggested that the interstellar object we now know as Oumuamua might be a spaceship, a lightsail, from an alien civilization. “But we should examine anything that enters the Solar System from interstellar space in order to infer the true nature of `Oumuamua or other objects of its mysterious population,” he added.
In October 2018, Loeb published a study that “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.
Now, two years later, on September 8, 2019, a computer program nicknamed “Interstellar Crusher” created by astronomers at Jagiellonian University in Krakow, Poland that scanned tirelessly through online data of newly-found comets and asteroids, issued a red alert and notified the team of a possible second hyperbolic object arriving from interstellar space some two years after our first interstellar visitor, the infamous ‘Oumuamua.
“This code was written specifically for this purpose, and we really hoped to receive this message one day. We only didn’t know when’, said Piotr Guzik. The body had been first spotted by Gennady Borisov a week earlier, although its identity had been unknown at that time. A closer investigation into the object’s orbit confirmed its exosolar origin, making it the second-known interstellar interloper.
Two days after receiving the alert, the team was already scrutinizing the first images of the object obtained at the William Herschel Telescope on La Palma, Spain, and getting ready to receive more data from the larger Gemini North Telescope on Mauna Kea, Hawaii. The photographs were obtained in two color bands and provided the first astrophysically significant glimpse of the body. ‘
“We immediately noticed the familiar coma and tail that were not seen around ‘Oumuamua’, said Michał Drahus. ‘This is really cool because it means that our new visitor is one of these mythical and never-before-seen “real” interstellar comets’, Drahus said. It took proper measurements before the team could determine the comet’s color and estimate its other properties. They have found that comet Borisov has a dust-dominated morphology, a reddish hue, and that its solid nucleus is about 1 km in radius. ‘Make of this what you will, but based on these initial characteristics, this object appears indistinguishable from the native Solar System comets’, said Guzik.
The team’s research is only a prologue to a more thorough investigation. ‘The comet is still emerging from the Sun’s morning glare and growing in brightness. It will be observable for several months, which makes us believe that the best is yet to come’, said Wacław Waniak one of the co-author of the study. The team still has a considerable amount of observing time reserved on the Gemini North Telescope, and they had booked a large slot on the European Southern Observatory’s Very Large Telescope well ahead of Borisov’s discovery.
‘We can safely say that research on this body will be transformative for planetary astronomy and a milestone for astronomy in general’, Guzik said.
Flashback to Oumuamua & Beyond
Flashing back to when Oumuamua entered our Solar System, “it spun around over a period of eight hours its brightness changed by a factor of 10′” Loeb observed in an interview with Endless Thread. “And that’s much more than any object born in the solar system, such as asteroids or comets, that change by at most a factor of three or so.”
Another weird anomaly, Loeb said, was the mere fact that it was discovered, [which] implies that the population of such objects is much more abundant than we anticipated. Unless of course it’s on a very specialized orbit such that it’s not a member of a population of random objects.
“The entire discussion about Oumuamua is very similar to an imaginary scene where you see a cave person being shown an iPhone. And this cave person would look at it and think that it might be a rock. And then would show it to other members of his or her tribe and the people there would still say, No, it’s probably a rock and how dare you say something else, how dare you talk about something that is different than a rock because rocks are everything that we are familiar with.
“And so, to me,” Loeb concludes, “not even putting aliens on the table for discussion is a crime! Because if you look at the history of science, you know, Galileo Galilei argued that the Earth moves around the sun and he was put under house arrest for that. Now, this of course didn’t change the facts. It doesn’t matter what is being said on Twitter, what is being said in other social media or among scientists. This thing is what it is, right? And, you know, the Earth still moves around the sun irrespective of what the church said a while ago. And the fact that Galileo suffered for it has no relevance to nature.”
Image credit: Caltech/JPL