Global Courant
On January 8, 2014, a fireball from space shot through Earth’s atmosphere and crashed into the sea, north of the island of Manus off the northeast coast of Papua New Guinea. The location, speed and brightness were recorded by US government sensors and quietly tucked into a database of similar events.
That data lay dormant for five years, a source of contention until Avi Loeb, a theoretical astrophysicist at Harvard University, and Amir Siraj, then a student at the university, stumbled upon it in 2019. Based on the recorded speed and direction, Mr. Siraj identified the fireball as an extreme outlier.
Last month, Dr. Loeb led an expedition to retrieve fragments of the fireball from the western Pacific. On June 21, he has claimed that he had. And that, he says to the chagrin of many of his colleagues, could be evidence of extraterrestrial life.
“Not biological creatures, like you see in sci-fi movies,” said Dr. Loeb. “It is most likely a technological gadget with artificial intelligence.”
However, many astronomers see the announcement as the latest example of Dr. Loeb making a bizarre statement that is too strong and hasty. His statements (and a promotion video in Times Square about the search for extraterrestrial life) distort public perceptions of how science actually works, they say.
“People are tired of hearing about Avi Loeb’s wild claims,” said Steve Desch, an astrophysicist at Arizona State University. “It’s polluting good science — mixing the good science we’re doing with this ridiculous sensationalism and sucking all the oxygen out of the room.”
Dr. Desch added that several of his colleagues now refused to participate in Dr. Loeb in peer review, the process by which scholars evaluate each other’s research to ensure that only high-quality studies are published. “It’s a real breakdown of the peer review process and the scientific method,” he said. “And it’s so demoralizing and exhausting.”
Dr. Loeb also started the fireball catalog from the Center for Near Earth Object Studies at NASA. That led to the object detected in 2014. From the direction and velocity at impact – 28 miles per second – Dr. Loeb and Mr. Siraj that the fireball was moving too fast for something gravitationally bound to our sun. That meant that, like Oumuamua, it must also have been interstellar.
They wrote one paper about the discovery in 2019. It was initially rejected by The Astrophysical Journal, but the same journal then accepted it for publication last November, several months after the US Space Command announced in a memo posted on Twitter that measurements of the fireball’s velocity were accurate enough to deduce its interstellar origin.
That appeal to authority isn’t enough, said Peter Brown, a meteor physicist at Western University in Ontario. It is not known how accurate the US Department of Defense data is, which affects the likelihood that the object came from outside.
“We know from experience, using ground radar and optical networks, that you often find that a few percent of all the events you detect appear to be interstellar,” said Dr. Brown. To date, he continued, almost all of those events could be attributed to measurement errors.
Dr. Brown and others have also been troubled by Dr. Loeb to the community of experts studying fast-flying fireballs.
The recent ocean expedition of Dr. Loeb to recover the remains of the meteor in question was funded with $1.5 million from cryptocurrency entrepreneur Charles Hoskinson and organized through EYOS Expeditions. The voyage took place about 60 nautical miles north of Manus Island along the expected path of the 2014 fireball. A group of scientists, engineers and sailors and a film crew, as well as Mr. Hoskinson, accompanied Dr. Loeb. He’s documented the journey and its aftermath in a 42-part (and counting) series of self-published blog posts.
For two weeks, the science team dragged a custom-built sled equipped with magnets, cameras and lights across the seafloor, returning it at regular intervals to look for metal bits from the 2014 fireball stuck to the surface. In the end, they found dozens of shiny beads, each less than a millimeter in diameter. Preliminary analyzes performed on the ship showed that these spheres were made primarily of iron, with smaller amounts of other metals.
That’s not common in the waters around Manus Island, said Maurice Tivey, a marine geophysicist at Woods Hole Oceanographic Institution who was not involved in the expedition but once used underwater robots to map that part of the seafloor. Instead, sediments and volcanic ash are fertile — material that doesn’t move much once it settles on the ocean floor.
That, coupled with the roundness of the recovered fragments—suggesting they were once aerodynamic—drew Dr. Tivey pretty convincing. “So I think he found pieces of it,” he said.
Skepticism about the endeavor has flared up recently Asteroids, comets, meteor conference that happened while the deep-sea expedition was underway. There Dr. Desch suggests that if the fireball had been moving as fast as reported, there would have been nothing to find — the meteor would have completely burned up in the atmosphere. Even in the most generous scenario, he said, only a milligram of material would have survived and would have been scattered over dozens of square miles along the ocean floor.
Dr. Also presenting at the conference, Brown described a recent analysis using data from an assortment of instruments to compare measurements for 17 of the objects listed in the same NASA fireball catalog used by Dr. Loeb and Mr. Siraj. Are Resultsthat have been accepted for publication in The Astrophysical Journal indicate that the catalog data often indicates incorrect directions and velocities and that the size of the velocity measurement error increases for objects with greater velocity.
Those errors are big enough to move the 2014 fireball from an untethered trajectory to a bounded trajectory, Dr. Brown — meaning it might not have been interstellar after all. He found that if the object had actually been traveling at nearly 12 miles per second on impact, the reported brightness, density, and drag would better fit theoretical models of meteors.
Based on that, Dr. Brown that the fireball most likely hit at a slower speed. “If the speed was overestimated, the object is more or less within the range of what we see in terms of other bound objects in the solar system,” he said.
Dr. Loeb disagreed with that pushback.
“When I was trained as a physicist, I was told that when you have a model and it doesn’t match the data, it means you need to revise your model,” he said, referring to measurements in NASA’s catalog.
He also believes, unlike many of his colleagues, that the US military’s sensors are reliable, even if he doesn’t have access to their raw readings. “They are responsible for national security,” said Dr. Loeb. “I think they know what they’re doing.” That he and his team found what they believe are fragments of the 2014 meteor at the location indicated by those measurements only boosts his confidence.
It is unlikely that the government will disclose how precise the data is from those devices. Dr. So Loeb is counting on a different kind of evidence: He sent the spheres to laboratories at Harvard University, the University of California, Berkeley and the Bruker Corporation in Germany for thorough analysis and dating. Spheres older than our solar system, or with a clear isotopic signature, must be interstellar.
At Berkeley, Dr. Loeb conducted some of the initial inspections himself. Early tests revealed the presence of uranium and lead, the abundance of which can be used to estimate the material’s age. Two of the spherules found along the fireball’s expected path appear to be as old as the universe itself, Dr. Loeb.
That’s in contrast to a spherule recovered at a distance from the fireball’s path, which Dr. Loeb expects it to be either geological in origin or from another meteorite. He estimated that this sphere is a few billion years old, similar to that of our solar system.
But even if the fireball really came from a different cosmic environment, much more evidence is needed to show that the balls are related to extraterrestrial life.
According to Don Brownlee, an astronomer at the University of Washington who used magnets to collect cosmic marbles from the seafloor in the 1970s, the spheres that don’t contain nickel probably didn’t come from a natural meteorite. On the other hand, he says, if no oxygen is found, the material is unlikely to have passed through Earth’s atmosphere. Dr. Loeb has already done that written that early results revealed an absence of nickel, but he did not mention oxygen.
He is open to the possibility that he is mistaken, but he also likes to call on scientific celebrities in response to such concerns. “Einstein was wrong three times,” he said, referring to supermassive black holes, gravitational waves and quantum entanglement — all discoveries that have since been recognized with Nobel Prizes in physics. “It’s valuable to test ideas experimentally,” said Dr. Loeb. “Let the evidence be the guide.”
According to dr. Desch believes the meteor community there are interstellar objects out there, and they’re eager for one to hit Earth — there’s just not strong evidence yet that it happened. “I want to assure the public that scientists are not making things up,” he said. “What the public sees in Loeb is not how science works. And they shouldn’t go away thinking that.”
The public can hear more from Dr. Loeb about extra bits of rock from the bottom of the sea. Later this year, his team plans to return to the waters north of Papua New Guinea to hunt for larger relics from the 2014 fireball. And in 2024, the team says it will visit a site off the coast of Portugal in search of the remains of a second meteor. Dr. Loeb and Mr. Siraj have claimed is of interstellar origin.
“He may be wrong,” said Rob McCallum, co-founder of EYOS Expeditions and the main organizer of the recent expedition, adding, “but we’ll never know unless we look.”
