The United States Space Command released a memo on April 6 verifying the first interstellar meteor that crash-landed on Earth. An interstellar meteor is a rock whose origins are from outside our solar system. Identifying objects passing through our solar system is considered rare, let alone discovering one that ended up here on Earth.
The memo confirms the findings of Harvard astronomers Amir Siraj and Abraham Loeb back in 2019. They discovered that a meteor that crash-landed along the northeast coast of Papua New Guinea on January 8, 2014, was actually of interstellar origin.
6/ “I had the pleasure of signing a memo with @ussfspoc’s Chief Scientist, Dr. Mozer, to confirm that a previously-detected interstellar object was indeed an interstellar object, a confirmation that assisted the broader astronomical community.” pic.twitter.com/PGlIOnCSrW
— U.S. Space Command (@US_SpaceCom) April 7, 2022
Siraj was initially studying Oumuamua, the first known interstellar object observed in our solar system that was identified in 2017. He was conducting his undergraduate research with Loeb, a science professor at Harvard University.
Oumuamua was a large, oval-shaped asteroid that passed through the solar system but never hit Earth or got close enough for better inspection.
Loeb and Siraj began digging up historical data from NASA’s Center for Near-Earth Object Studies (CNEOS) to look for smaller meteors that might have been from outside the solar system. In their search, the pair came across the records of CNEOS 2014-01-08.
There were about 1,000 crash-landings recorded in NASA’s CNEOS database, but the 2014 meteor caught Siraj’s attention because of its uncanny speed. This lightning pace hinted at “a possible origin from the deep interior of a planetary system or a star in the thick disk of the Milky Way galaxy,” wrote their 2019 study.
CNEOS 2014-01-08 was moving at a speed of 28 miles per second relative to Earth, while the Earth is orbiting around the sun at around 18.6 miles per second. However, this was inaccurate given the researchers were calculating the speed of the meteor while also being on a moving object.
After adjustments were made, Siraj and Loeb’s calculations concluded that the meteor was actually traveling at approximately 37.7 miles per second, this time relative to the sun.
“It was really fast, and so I was like: ‘Oh my God, this could be an interstellar meteor,’” Siraj said. “It was hiding in plain sight. It wasn’t that we had to dig to find this database. It was more that there hadn’t been an interstellar object until 2017. As a result, no one had a reason to think that there could be meteors that were from outside of the solar system.”
Siraj mapped out the path of the object and discovered its orbit was unbound. This means that rather than revolving around the sun, it had been slingshotted from outside our solar system.
“Presumably, it was produced by another star, got kicked out of that star’s planetary system, and just so happened to make its way to our solar system and collide with Earth,” Siraj said.
Meteor Research is Now Out of Limbo
Siraj and Loeb submitted their findings to The Astrophysical Journal Letters but were later declined because of missing data withheld from the CNEOS database.
This is because the sensors that detect meteors are used by the Pentagon. The same technologies are used to monitor the skies for possible nuclear warheads. The classified data sent the research into limbo as Siraj and Loeb tried to get the US government to confirm their findings.
After years of navigating government bureaucracy, they finally received official verification that CNEOS 2014-01-08 was indeed interstellar. The confirmation came from the Deputy Commander of Space Command, John Shaw.
“Dr. Joel Mozer, the Chief Scientist of Space Operations Command, the United States Space Force service component of U.S. Space Command, reviewed analysis of additional data available to the Department of Defense related to this finding. Dr. Mozer confirmed that the velocity estimate reported to NASA is sufficiently accurate to indicate an interstellar trajectory,” wrote Shaw in the letter.
The news came as a surprise to Siraj, who had already moved on to other research.
“I thought that we would never learn the true nature of this meteor, that it was just blocked somewhere in the government after our many tries, and so actually seeing that letter from the Department of Defense with my eyes was a really incredible moment,” Siraj said.
Since hearing the news of the confirmation, Siraj has assembled a team to renew efforts that will hopefully get their research published this time around. He believes that the scientific community can build upon their initial findings with more specialized research.
“Given how infrequent interstellar meteors are, extra-galactic meteors are going to be even rarer,” Siraj warned.
”But the fact of the matter is, going forward, we won’t find anything unless we look for it. We might as well take it upon ourselves as scientists to build a network as extensive as the U.S government’s sensor network, and use it for the purposes of science and fully use the atmosphere.”