In this image, Oumuamua looks a bit like a fleshy Millennium Falcon, but it could be a remnant of a Pluto-like planet.
William Hartmann
Since we were visited by Oumuamua, the first interstellar object we saw wandering our solar system, scientists are fascinated by it. It’s an enigmatic cosmic vagabond – so weird that some scientists have it even assumed it could be some piece of alien technology (although there is no real proof of that.)
A new theory, appearing in two articles published Tuesday in the Journal of Geophysical Research: Planets, states that the strange object could be an ejected piece of a Pluto-like planet that was removed from its own solar system about 400 million years ago. shot. .
“This research is exciting because we’ve probably solved the mystery of what Oumuamua is,” said Steven Desch, an astrophysicist at Arizona State University and co-author of the new studies. “We can reasonably identify it as a chunk of an ‘exo-Pluto,’ a Pluto-like planet in another solar system.”
Oumuamua (Hawaiian for ‘scout’ or ‘messenger’) was discovered in 2017 as it circled the sun on its way out of our solar system. It was observed in October and November 2017 before disappearing into the dark.
And it was weird.
It showed strange behavior. Observations suggested it was cigar-shaped, and as it circled the sun it took a lot of speed – more than expected – without showing any signs of escaping gas, a telltale marker of a comet.
Read more: Harvard’s Avi Loeb was more certain than ever that we were being visited by alien spacecraft
Desch and co-author Alan Jackson believe that in another planetary system somewhere in space half a billion years ago, a collision between two cosmic bodies caused explosive nitrogen ice emissions. A pancake-shaped block was hurled from his home into space between planetary systems.
In the frigid depths of the cosmos, this solid block of nitrogen would wander and be slowly ejected by radiation. As it entered our solar system and approached the sun, the nitrogen warmed up, giving it a small speed boost, while also producing the cigar shape that Earth observers noticed. Jackson says the heating would have flattened the object, much like the outer layers of a bar of soap rub off during use.
It’s a neat statement, explaining all of Oumuamua’s strangeness, and it’s an exciting hypothesis because it suggests that Oumuamua is the first bit of an exoplanet to visit our solar system.
Oumuamua’s reflectivity also matched what astronomers observed on Pluto and Neptune’s moon Triton, which are nitrogen-rich. In a very young solar system, where bodies constantly bumped into each other, it’s reasonable to think that chunks were thrown for a wild ride through space and that we happened to see one pass by.
“We reasoned it was possible that there were Plutos in other solar systems with nitrogen ice on their surface and a chunk off could have entered our solar system and explained everything we saw,” Desch said.
And that, he said, puts a damper on the alien spacecraft theory.
“Everyone is interested in aliens, and it was inevitable that this first object outside the solar system would make people think of aliens,” said Desch. “But it’s important in science not to jump to conclusions.”
So far, scientists have discovered only two interstellar objects. The second, 2I / Borisov, was found at the end of 2019 and was fairly common in comparisonIt was almost certainly a comet, but he surprised scientists with some unique properties
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