Oumuamua has been spinning chaotically through space for millennia. Researchers said that this has something to do with the cigar-shaped object's violent past.
Oumuamua
Oumuamua is the first known interstellar object to pass through the Solar System. The object was first detected flying in September and was initially thought to be a comet. Researchers later realized it was an asteroid.
Now, researchers reported new discoveries about the object's origins and its journey.
Not Spinning Periodically
Wes Fraser, from Queen's University Belfast, and colleagues who have been analyzing the brightness measurement of the object found that unlike most bodies in the Solar System, Oumuamua does not spin periodically. Instead, it tumbles, or spins chaotically, through space and could have been this way for many billions of years.
Scientists have long suggested that the asteroid has been traveling through the Milky Way for millions of years before it entered the Solar System.
The researchers also reported that modeling of the body suggests that it will continue to spin chaotically for many billions of years before internal stress causes it to rotate normally again.
"Assuming a body that responds to non-principal axis rotation in a similar manner to Solar System asteroids and comets, the timescale to damp 1I/'Oumuamua's tumbling is at least one billion years," the researchers wrote in their study.
"1I/'Oumuamua was probably set tumbling within its parent planetary system and will remain tumbling well after it has left ours."
A Violent Past
Although the exact reason for the object's spinning isn't clear, researchers think that Oumuamua collided with another object in the past and this violently threw it out of its home system and into the interstellar space.
Researchers, however, cannot get a high-resolution image of the object to see the kind of crater that it has, which can shed light on the collision that caused Oumuamua to start tumbling.
"It was most likely sent tumbling by an impact with another planetesimal in its system, before it was ejected into interstellar space," Fraser said.
"This space cucumber had origins around another star, has had a violent past, and tumbles chaotically because of it."
The torque already reshaped the object over the time it has spun violently through space. Once it soaks up all of the energy, the object will glide gently through space.
Fraser and colleagues reported their findings in a study published in journal Nature Astronomy on Feb. 9.
