Since we were visited by Oumuamua,, scientists have been captivated by it. He is a puzzling cosmic wanderer, so strange that some scientists have (although there is no real evidence for that).
A new theory, appearing in two articles published Tuesday in the Journal of Geophysical Research: Planets, posits that the strange object could be a piece ejected from a Pluto-like planet that was ejected from its local solar system about 400 million years ago. years. .
“This research is exciting because we have probably solved the mystery of what Oumuamua is,” said Steven Desch, an astrophysicist at Arizona State University and a co-author of the new studies. “We can reasonably identify it as a piece of an ‘exo-Pluto,’ a Pluto-like planet in another solar system.”
Oumuamua (Hawaiian for “scout” or “messenger”)while circling the sun as it exited our solar system. It was observed in October and November 2017 before disappearing into obscurity.
And it was strange.
He showed strange behavior. Observations suggested that it was shaped like a cigar and, as it circled the sun, it acquired great speed, faster than expected, showing no signs of gas leakage, a tell-tale indicator of a comet.
Desch and co-author Alan Jackson believe that in another planetary system, somewhere in space 500 million years ago, a collision between two cosmic bodies caused an explosive expulsion of nitrogen ice. A block in the shape of a pancake was thrown from its home into the space between the planetary systems.
In the icy depths of the cosmos, this solid block of nitrogen would wander, slowly being splintered by radiation. As it entered our solar system and approached the sun, the nitrogen heated up, giving it a small boost of speed, at the same time producing the cigar shape that observers on Earth noticed. Jackson says heating would have flattened the object, much like the way the outer layers of a bar of soap rub off during use.
It’s a clear explanation, explaining all the strangeness of Oumuamua, and it’s an exciting hypothesis because it suggests that Oumuamua is the first piece of an exoplanet to have visited our solar system.
Oumuamua’s reflectivity also matched what astronomers have observed on Pluto and Neptune’s moon Triton, which are rich in nitrogen. In a young and distant solar system, where bodies were constantly colliding with each other, it is reasonable to think that chunks were thrown on a wild journey through space and that we happened to see one pass by.
“We reasoned that it was possible that there were Plutos in other solar systems with nitrogen ice on their surfaces and a detached part could have entered our solar system and explained everything we saw,” Desch said.
And that, he said, puts a brake on the theory of extraterrestrial spacecraft.
“Everyone is interested in aliens and it was inevitable that this first object outside the solar system would make people think of aliens,” Desch said. “But in science it is important not to jump to conclusions.”
So far, scientists have discovered only two interstellar objects. The second,, was found at the end of 2019 and . It was almost certainly a comet, but .
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