CAMBRIDGE, Mass. — Sifting through spherules from the ocean floor isn’t your typical summer project, but for Harvard Prof. Avi Loeb, there’s nothing he’d rather be doing.
Spherules, he explains, are basically small metallic marbles. The Israeli theoretical physicist and former head of the Harvard astronomy department traveled a long way to find them — Papua New Guinea’s Manus Island, where he and a research team researched from June 14 to 28.
Loeb posits that they come from the first interstellar object detected by humanity, a meteor that exploded in the Earth’s atmosphere, above Papua New Guinea on January 8, 2014. What’s more, he suggests, this meteor might represent extraterrestrial technology.
“The first thing to do is figure out whether the material identity looks different from solar system material,” Loeb told The Times of Israel over Zoom. “It would be the first time humans put their hands on material from a large object coming from outside the solar system, the first meteor inferred to be from interstellar space. That’s a discovery by itself.”
“The next question,” he said, “is whether it’s technological in origin, droplets melted from a semiconductor or electric circuit.”
Loeb is no stranger to making daring claims, whether about this meteor or ‘Oumuamua, a mysterious pancake-shaped object detected passing through the solar system in 2017, which he deemed to also be interstellar and — potentially — a piece of alien technology.
“If we find a partner in interstellar space, it will change the future of humanity,” Loeb said. “It will change our aspirations for space, it will change the way we treat each other. It will just be the biggest impact science can have on society.”
Casually dressed in a red short-sleeve shirt, Loeb was in classic form during the interview, explaining methods and findings in relatable ways. He likened the spherules to Russian matryoshka dolls, noting that some contain smaller spherules within larger ones. When his team found the first spherule after nearly a week of trying, why was he confident of more? It was like ants in a kitchen: finding one implies many others, he said.
He learned about the 2014 meteor five years after it exploded, in 2019. His research assistant, then-Harvard student Amir Siraj, found it in an online catalog of 273 meteors from the Center for Near-Earth Object Studies (CNEOS), part of NASA’s Jet Propulsion Laboratory. The Jan. 8, 2014, meteor stood out for several reasons.
“This meteor moved too fast to be bound gravitationally to the sun,” Loeb said. “We extrapolated the speed to outside the solar system. It was likely not bound, at 60 km/s [37 mps] relative to the Milky Way … 60 km/s implied it was faster than 95%of all stars in the vicinity of the sun.”
Then, Loeb said, “We were able to calculate the object was able to withstand much more stress than any other meteor in the catalog.”
From what he inferred about its speed and strength, he made another suggestion.
“It raised the possibility that it might be a spacecraft, professionally manufactured by an extraterrestrial civilization from an alloy tougher than iron meteors,” Loeb said. “It was not a philosophical question if there were any fragments left over.”
Loeb and Siraj submitted a research paper on the meteor. According to Loeb, the scientists refereeing their submission rejected it because the government data did not include error bars or uncertainties.
In 2022, U..S Space Command released a statement backing up Loeb’s claim that the meteor was interstellar with 99.999% certainty. He felt vindicated enough to organize a team to plumb the seabed off Papua New Guinea for traces of the meteor.
Crypto mogul Charles Hoskinson serendipitously contributed $1.5 million, plus his private jet. Once in Papua New Guinea, the team used innovative technology. Their ship, the appropriately named Silver Star, featured a sled with molybdenum magnets on both sides to look for metallic particles on the seabed.
“The engineers were fantastic,” Loeb said. “It was a very big challenge finding these tiny droplets a half-meter [1.6 feet] in size across a region 10 square kilometers [roughly 4 square miles] in size provided by the Department of Defense as the location of the fireball.”
“As soon as the sled was on the [sea] floor, it collected mostly black powder, volcanic ash, the most abundant source of particles,” he said. “I was frustrated by the fact we could not see anything unusual.”
Six days went by. Loeb and the team did not rest. They used mesh to filter out any volcanic ash, looking at what was left through a microscope. The result: a eureka moment.
“Jeff Winn, a geologist on the team, ran down the stairs to call me: ‘We just saw a spherule!’” Loeb recalled. “It was amazing, one of the metallic marbles, very distinctive from its background.”
An analysis determined that the spherule was largely iron — 84 %. The team subsequently found around 360 such spherules.
They began collecting spherules to send to three separate locations for analysis — Harvard, the University of California at Berkeley and the Bruker Corporation in Germany. At Harvard, that analysis will be done by Loeb, colleagues in the Department of Earth and Planetary Science, and summer interns, including his daughter and newly-accepted first-year student, Lotem Loeb.
Researchers will use such factors as half-life, which “can be used to date the age of the material,” Loeb said. “We can, for example, infer that the material is much older than material from the solar system. That’s one way to tell the difference.”
Meanwhile, he’s facing scrutiny from multiple sources.
The Times of London has quoted several Papua New Guinea officials as asking whether Loeb had the proper paperwork to come to their country and take samples from the seabed. One of them was Penua George Polon, Manus Province’s deputy administrator.
“We’ve been cheated,” the outlet quoted him as saying. “They came here, no one knew about it and now they’ve gone. What have they found? Does it have value? Do we have rights over it? If it’s scientific research, how are our scientific institutions going to benefit?”
When The Times of Israel asked Loeb about such statements, he responded in an email that the team has been liaising with officials from Papua New Guinea for eight months and has made a collaborative research agreement with one of the country’s scientific institutions — the University of Technology.
“The materials we retrieved are 35 milligrams of tiny dust particles, with no commercial value,” Loeb said. “The reports were triggered by officials who were not in the loop.”
Around the same time as his expedition, two scholars published a paper questioning whether the meteor came from outside the solar system — “On the Proposed Interstellar Origin of the USG 20140108 Fireball,” by Peter G. Brown, chair of planetary science at the University of Western Ontario, and Jiří Borovička of the Astronomical Institute of the Czech Academy of Sciences.
“It concluded the government velocity measurements might be wrong, because their model for solar system rocks could not fit the data,” Loeb said. “They concluded that it was just a stony meteor, it could not be made of iron.”
He countered, “But at the time this paper was published, we have found the meteor’s spherules to be made mostly of iron. If your model does not fit the data, revise the model.”
Brown told The Times of Israel that the scientific community needs to see the original data on the meteor for Loeb’s claim of interstellar origin to be validated. Even the 2022 statement from U.S. Space Command left him unconvinced.
“It’s a classic appeal to higher authority, ‘We have to accept what they say is correct,’” Brown said. “That’s not the way science works. For such an extraordinary claim, the data has to be available for independent analysis.”
Another expert, Matthew Genge, a senior lecturer in earth and planetary science at Imperial College London, voiced doubts about the spherules Loeb’s team found.
“Just because something happens in a certain place doesn’t mean everything you find there is related to that event,” he said. “So that means you can’t use the location of an event as evidence of origin. It could be — but you can’t prove it.”
The composition of Loeb’s spherules includes iron and titanium, which makes Genge question interstellar origin. Were that the case, he said, these particles would have reacted to the oxygen in the atmosphere and made iron oxide.
“They don’t appear to be oxidized,” said Genge. “At present, they’re most likely artificial, they are terrestrial, made by us human beings from some process, either welding or the re-entry of a spacecraft.”
“I’m hoping I’m wrong,” he added. “It would be really cool if it was part of an alien spacecraft. I think the research group has an uphill struggle. It will be difficult for them to convince the scientific community that these are interstellar. We need really strong evidence.”
Loeb insists that’s what he’s working on. He continues to share his findings on Medium, noting on July 14 that the number of spherules has increased to 141, ready for analysis. He’s also awaiting the release of his next book, “Interstellar.” So is the public — it’s among the most-requested upcoming releases for August.
“I don’t [receive] any negativity coming from the general public, coming from the U.S. government,” Loeb reflected. “On the contrary, it’s all positive, all encouraging, all open-minded. Why is it so difficult for people in academia to be open-minded?
“Science is not always about what we know. If there’s evidence, we should accept it and try to figure out what it means,” he said. PJC