It is now confirmed what two researchers have been trying to prove for three years: that in 2014 a meteor traveled a long way from home to visit Earth.
A group of investigators has discovered the first known case of an interstellar meteor hitting Earth, confirms a recently released US Space Command report. An interstellar meteor is a space rock that originates outside our solar system – which is a rare occurrence. This one is known as CNEOS 2014-01-08, and it crashed along the northeast coast of Papua New Guinea on January 8, 2014.
The discovery came as a surprise to Amir Siraj, who identified the object as an interstellar meteor in a 2019 study he co-authored while a graduate student at Harvard University.
Siraj was then, with Abraham Loeb, professor of science at Harvard University, investigating ʻOumuamua, the first known interstellar object in our solar system, which was found in 2017. Siraj decided to go through the database of the Center for the Study of Objects. NASA’s Near-Earth to look for other interstellar objects and within days found what he believed to be an interstellar meteor.
It was the meteor’s high speed that initially caught Siraj’s attention. The meteor was traveling at a speed of about 45 kilometers per second relative to Earth, which moves at about 30 kilometers per second around the sun. Because the researchers measured how fast the meteor was traveling while it was on a moving planet, the 45 kilometers per second didn’t really show how fast it was moving.
Heliocentric velocity is defined as the meteor’s velocity relative to the sun, and this is a more accurate way of determining an object’s orbit. It is calculated based on the angle at which a meteor strikes Earth. The planet moves in one direction around the sun, so the meteor could have hit the Earth head-on, i.e. in the opposite direction to the direction the planet is moving, or from behind, in the same direction the Earth is moving. move.
As the meteor hit Earth from behind, Siraj’s calculations showed that the meteor was indeed traveling at about 60 kilometers per second relative to the sun.
Then he mapped the meteor’s trajectory and found that it was in a free orbit, as opposed to the closed orbit of other meteors. This means that instead of circling around the sun like other meteors, it came from outside the solar system.
“Presumably, it was produced by another star, was ejected from that star’s planetary system, and happened to arrive in our solar system and collide with Earth,” Siraj said.
Loeb and Siraj were unable to publish their findings in a journal because their data came from NASA’s CNEOS database, which does not disclose information such as the accuracy of the readings.
After trying for years to obtain the additional information they needed, they received official confirmation from John Shaw, deputy commander of the US Space Command, that it was, in fact, an interstellar meteor. The command is part of the US Department of Defense and is responsible for military operations in outer space.
“Joel Mozer, Chief Scientist, Space Operations Command, United States Space Force service component of the U.S. Space Command, reviewed the analysis of additional data available to the Department of Defense related to this discovery. Mozer confirmed that the estimate of velocity reported to NASA is sufficiently accurate to indicate an interstellar trajectory,” Shaw wrote in the letter.
Siraj had moved on to other investigations, however, and had almost forgotten about her discovery. So receiving the document was a shock.
“I thought we would never know the true nature of this meteor, that it was blocked somewhere in the government after our many attempts, and then seeing that letter from the Department of Defense with my eyes was really an incredible moment,” Siraj said.
A second hypothesis
Since receiving confirmation, Siraj said his team has been working to resubmit their findings for publication in a scientific journal. Siraj would also like to assemble a team to try to recover part of the meteor that fell into the Pacific Ocean, but admitted that would be an unlikely possibility given the scale of the project.
If researchers could get their hands on the “Holy Grail of interstellar objects,” it would be scientifically disruptive and allow scientists to discover more about the world beyond our solar system, Siraj said.
NASA and the US Space Command began by not commenting.
Source: With Agencies