A meteor traveled a long way from home to visit Earth.
Researchers have discovered the first known interstellar meteor to ever hit Earth, according to a recent US Space Command document. The interstellar meteor is a cosmic rock that originates outside our solar system – a rare phenomenon.
This one is known as CNEOS 2014-01-08 and made an emergency landing on the northeast coast of Papua New Guinea on January 8, 2014.
The find came as a surprise to Amir Siraj, who identified the object as an interstellar meteor in a 2019 study he co-authored while a student at Harvard University.
Siraj is investigating ʻOumuamua, the first known interstellar object in our solar system, discovered in 2017, with Abraham Loeb, a professor of science at Harvard University.
Siraj decided to go through the database of the NASA’s Near-Earth Object Research Center to find other interstellar objects and discovered what he thought was an interstellar meteor within days.
The high speed of the meteor was what initially caught Siraj’s eye.
The meteor was traveling at a high speed of about 28 miles per second (45 kilometers per second) relative to the Earth, which was moving at about 18.6 miles per second (30 kilometers per second) around the sun. Because researchers measure how fast a meteor moves while on a moving planet, 45 kilometers per second is not really how fast it moves.
The heliocentric velocity is defined as the speed of the meteor relative to the sun, which is a more accurate way to determine the orbit of an object. It is calculated based on the angle at which the meteor hits the Earth. The planet moves in one direction around the sun, so that the meteor could hit the Earth head-on, which means that it is opposite to the direction in which the planet is moving, or behind, in the same direction as the Earth is moving.
Because the meteor hit the Earth from behind, Siraj’s calculations say that the meteor is actually moving at about 37.3 miles per second (60 kilometers per second) relative to the sun.
He then mapped the trajectory of the meteor and found that it was in an unbound orbit, unlike the closed orbit of other meteors. This means that instead of orbiting the sun like other meteors, it comes from outside the solar system.
“It’s supposed to be made by another star, ejected from that star’s planetary system, and it just happened to make its way to our solar system and collide with Earth,” Siraj said.
DIFFICULTY TO PUBLISH
Loeb and Siraj were unable to publish their findings in a journal because their data came from NASA’s CNEOS database, which did not disclose information such as how accurate the testimony was.
After years of trying to obtain the necessary additional information, they received official confirmation that it was in fact an interstellar meteor, from John Shaw, Deputy Commander of the US Space Command. The command is part of the US Department of Defense and is responsible for military operations in space.
“Dr. Joel Moser, chief scientist of the Space Operations Command, the U.S. Space Forces Service Command, reviewed the analysis of additional data available to the Department of Defense related to this discovery. “Dr. Moser confirmed that the speed estimate reported to NASA is accurate enough to indicate an interstellar trajectory,” Shaw wrote in the letter.
6 / “I had the pleasure of signing a note with @ussfspoc’s chief scientist, Dr. Moser, to confirm that a previously discovered interstellar object is indeed an interstellar object, a confirmation that has helped the wider astronomical community.” Pic.twitter .com / PGliONCSrW
– US Space Command (@US_SpaceCom) April 7, 2022
Siraj had switched to other research and almost forgot about his discovery, so the document came as a shock.
“I thought we would never learn the true nature of this meteor, that it was just blocked somewhere in the government after our many attempts, and so I actually saw this letter from the Ministry of Defense with my own eyes was a truly amazing moment,” Siraj said.
After receiving the confirmation, Siraj said his team was working to re-present its findings for publication in a scientific journal.
Siraj would also like to assemble a team to try to retrieve some of the meteor that landed in the Pacific, but acknowledged that this would be unlikely due to the large size of the project.
If researchers can touch the “holy grail of interstellar objects,” Siraj said it would be scientifically innovative to help scientists discover more about the world outside our solar system.
NASA and the US Space Command initially declined to comment.