An extremely elongated, cigar-shaped asteroid entered our solar system a while ago, and scientists started believed it may be an alien spaceship built by an advanced extraterrestrial civilization.
Later studies showed it wasn’t ET’s spacecraft, just an odd space rock.
Now, astronomers think they have solved one of the biggest mysteries surrounding the weird-looking space rock dubbed ‘Oumuamua, the very first observed extraterrestrial object that entered our solar system from deep space. ‘Oumuamua was spotted on October 19, 2017, using the Pan-STARRS telescope located on the island of Maui.
A group of experts including members from NASA’s Jet Propulsion Laboratory has released the results of a recent study that aims to get to the bottom of ‘Oumuamua’s origin.
‘Oumuamua is around 400 meters long, and as it was spotted traveling through our solar system, scientists thought it may be an alien reconnaissance craft.
However, ‘Oumuamuawas found to be far from an alien craft. It is a space rock that formed in a distant solar system.
But a question that has bothered scientists since the discovery of the mysterious object was; if it came from another solar system, how did it get here, and where did it travel from?
Now, a scientific paper published in the Astrophysical Journal looks into the origins of ‘Oumuamua.
Scientists calculated the trajectory of the object and tried figuring out what star system it came from.
The study concludes that ‘Oumuamua most likely left its home star system millions of years ago.
It made its way to our cosmic neighborhood after it was most likely ‘expelled’ from its star system during the formation of planets.
Using ESA’s Gaia stellar surveyor, astronomers have identified four possible star systems that are possible home systems of ‘Oumuamua.
“Gaia is a powerful time machine for these types of studies, as it provides not only star positions but also their motions,” explains Timo Prusti, Gaia project scientist at ESA.
Scientists identified four stars “whose orbits had come within a couple of light years of ‘Oumuamua in the near past, and with relative velocities low enough to be compatible with likely ejection mechanisms,” explains an article by the European Space Agency.
All of the four candidates happen to be dwarf stars which have a mass similar or smaller than our Sun. These distant stars are thought to have had their ‘close’ encounter with the interstellar comet between one and seven million years ago.
But there is just one small problem.
None of the stars identified by astronomers are known to have planets or to be part of a binary stellar system, meaning they would lack the requirement to be able to eject a small body such as Oumuamua from the system.
This means that either scientist are wrong about the origin of the object, or we just haven’t found planets and companion stars that may have helped expel the strange object millions of years ago.
“While it’s still early to pinpoint ‘Oumuamua’s home star, this result illustrates the power of Gaia to delve into the history of our Milky Way galaxy,” concludes Prusti.