Astronomers who claim to have spotted an interstellar meteor hitting Earth are trying to raise $1.6 million to mount an expedition to search for fragments that may remain on the sea floor north of Papua New Guinea. But the claim 鈥� which was endorsed by the US Department of Defense 鈥� remains controversial and other researchers say the odds of finding anything are minimal.
There have only been two confirmed observations of interstellar objects: 鈥�Oumuamua, a cigar-shaped asteroid first spotted in 2017, and Borisov, a comet seen in 2019. A few months before Borisov was discovered, and at Harvard University claimed to have identified an interstellar rock by crunching publicly available data collected from classified US government sensors, which cover nearly the entire Earth.
According to the pair, the roughly 0.5-metre-wide rock, called CNEOS 2014-01-08, entered Earth鈥檚 atmosphere from an interstellar trajectory in 2014 before burning up, but not everyone was convinced. The US government didn鈥檛 release measurement uncertainties for the data, which meant that the object couldn鈥檛 be verified as being interstellar.
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But in April this year, US Space Command, a division of the Department of Defense, released about the meteor, stating 鈥渢he velocity estimate reported to NASA is sufficiently accurate to indicate an interstellar trajectory鈥�. It still hadn鈥檛 released the actual uncertainties, but Loeb and Siraj were encouraged.
Alongside its statement, US Space Command also released a light curve for the meteor, a record of its brightness in Earth鈥檚 atmosphere over time which, Siraj says, can be used to infer the rock鈥檚 composition. In a new analysis, the pair say the meteor probably contained some form of iron, suggesting metallic fragments may have made it to Earth鈥檚 surface. 鈥淚t鈥檚 an extreme outlier in terms of composition, and it would be very difficult to get that kind of tensile strength without a lot of metal,鈥� says Siraj.
The sensor readings give a 10 by 10 kilometre area of the sky where the meteor entered the atmosphere. Using that information, along with models of winds and ocean currents, the pair say they have traced its final resting point to 100 square kilometres of the Bismarck sea, north of Papua New Guinea.
They now want to launch a 10-day expedition to collect possible meteorite fragments by towing a box covered in magnets across the ocean floor 鈥� as the fragments contain iron, they should be magnetic.
The pair hope to fund the $1.6 million expedition through private donations, though they are currently about a million dollars short. Siraj says they are already in contact with a number of oceanographic experts, including one who carried out a similar .
But there is still the problem of the missing data, even with the Department of Defense鈥檚 statement. 鈥淚 appreciate they鈥檝e stated this, and I respect that [US Space Command] obviously has a lot of analysis capability,鈥� says at Western University in Ontario, Canada. 鈥淏ut I don鈥檛 think the science community is going to buy into that unless the raw data is released, which I think is not likely.鈥�
Even if data for the original meteor fireball is released, the ocean depth and potential for strong ocean currents transporting the fragments away from the proposed search area makes success unlikely, says at Queen鈥檚 University Belfast, UK. 鈥淚t鈥檚 going to be much worse than looking for a needle in a haystack.鈥�
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