In a new study published this week in Astrophysical Journal Letters, two researchers say a meteor that crashed into Earth five years ago may be the only known object to visit our planet from beyond the solar system.
While examining data from the Center for Near-Earth Object Studies — which keeps records of times, dates, velocities and locations of incoming meteors — Harvard University professor Abraham Loeb and undergraduate student Amir Siraj quickly became interested in a particular one that slammed into Earth over Papua New Guinea on January 8, 2014.
The duo noticed the meteor had an unusually high rate of velocity, clocking in at 37 miles per second, which was too great of a speed for it to have been gravitationally tied to our sun’s orbit, According to National Geographic.
“I was very surprised,” Loeb told the magazine. “I didn’t expect that. I thought we will not see anything. But in retrospect, like any discovery, you say, Oh yeah, of course. How could I be so foolish not to look for that in the first place?”
Taking the object’s high velocity and trajectory, the researchers determined the meteor likely came hurtling toward Earth from another solar system light years away.
“What we did was take the properties of the meteor and take the velocity at the time of impact and extrapolate whether it was bound to the sun or not,” said Loeb, adding that the data pointed to the object originating from interstellar space, according to CNN. “At this speed, it takes tens of thousands of years for an object to move from one star to another.”
The nearest star system to ours is Alpha Centauri, a binary system 4.3 light years from Earth. Our solar system was recently visited by an interstellar object, though, when the cigar-shaped rock named ‘Oumuamua‘ came traveling by in 2017.
But of the space rocks that actually hit Earth, nearly all of them are from our own neighborhood.
“Almost all of the objects that hit the Earth originate for the solar system,” Loeb explained. “They are made of the same materials that made the solar system. Those that are interstellar originate from another source.”
If an interstellar object were to crash into the planet and be recovered, it could potentially give us vast knowledge of undiscovered worlds, Loeb told CNN.
“It’s sort of like getting a message in a bottle from a distant location,” he said. “We can actually examine it, just as if we were walking on the beach and looking at the seashells that are swept ashore, we could learn something about the ocean.”
Asteroids traveling through the vastness of space between solar systems and crashing into planets could also be a way that living organisms could spread around the universe.
“Most importantly, there is a possibility that life could be transferred between stars,” Loeb explained. “In principle, life could survive in the core of a rock. Either bacteria, or tardigrades (a microscopic, water-dwelling animal); they can survive harsh conditions in space and arrive right to us.”