Space Rock That Looks Like a Pancake Is Actually A Piece Of Planet

Space Rock That Looks Like a Pancake Is Actually A Piece Of Planet
Artist’s concept of the ‘Oumuamua interstellar object as a pancake-shaped disk. Credit: William Hartmann

A while back our galaxy was visited by an interstellar object. Known as ‘Oumuamua, scientists have puzzled over the makeup of this outside visitor for some time. Naturally, the internet went straight to thinking it was aliens, but new research suggests it may actually be the shard of a planet.

When ‘Oumuamua first zipped through our solar system back in 2017, scientists believed it to be a strangely flat comet. But it had just enough odd features to defy the classification of a comet or asteroid. So what is it?

What is ‘Oumuamua?

A new research paper suggests that ‘Oumuamua is actually a chunk of a long lost planet.

“This research is exciting in that we’ve probably resolved the mystery of what ‘Oumuamua is and we can reasonably identify it as a chunk of an ‘exo-Pluto,’ a Pluto-like planet in another solar system. Until now, we’ve had no way to know if other solar systems have Pluto-like planets, but now we have seen a chunk of one pass by Earth,” Steven Desch, an astrophysicist and one of the authors of the study, said in a statement.

The researchers think ‘Oumuamua could be made up of solid nitrogen, which is similar to the surface of Pluto. The shining of the ice is what gave away its composition.

“We realized that a chunk of ice would be much more reflective than people were assuming, which meant it could be smaller. The same rocket effect would then give ‘Oumuamua a bigger push, bigger than comets usually experience.”

As for how it got to our solar system? Scientists think an impact knocked a chunk out of a planet and it’s been hurtling through space ever since.

“It was likely knocked off the surface by an impact about half a billion years ago and thrown out of its parent system,” Alan Jackson, coauthor of the study, said.

Flat as a pancake

The shape of ‘Oumuamua has also puzzled researchers for some time. Its flat shape has been likened to a pancake or cookie but research suggests it wasn’t always this way.

“Being made of frozen nitrogen also explains the unusual shape of ‘Oumuamua. As the outer layers of nitrogen ice evaporated, the shape of the body would have become progressively more flattened, just like a bar of soap does as the outer layers get rubbed off through use,” Jackson said.

The researchers think that ‘Oumuamua lost 95% of its mass when it flew past our sun.

‘Oumuamua is only the second object identified to be from outside of our solar system. Researchers hope that future telescopes will be able to start finding even more interstellar objects to provide more information about outside galaxies.