Oumuamua
An artist's impression of Oumuamua. ESO/M. Kornmesser

'Oumuamua is the very first interstellar asteroid to visit our solar system and was first spotted by researchers in October 2017. Scientists have since attempted to study the mysterious space object to find out where it came from and what kind of cosmic event may have propelled its journey to our solar system.

A new study indicates that scientists may have finally figured out 'Oumuamua’s origin. Researchers believe 'Oumuamua likely came from a binary star system. Unlike our sun, binary star systems have only two stars orbiting a common center.

In order to determine the validity of this theory, researchers involved in the new study attempted to determine how common binary star systems are in the galaxy and how effective they are in ejecting objects.

The researchers discovered that binary star systems eject both rocky as well as icy objects. They also determined that rocky objects like 'Oumuamua are more likely to originate from binary star systems than from single star systems. Scientists also found that a “sufficient” number of such rocky objects exist in binary star systems, which in turn are highly efficient in ejecting them.

"It's really odd that the first object we would see from outside our system would be an asteroid, because a comet would be a lot easier to spot and the Solar System ejects many more comets than asteroids," lead author of the study Alan Jackson, a postdoc at the Centre for Planetary Sciences at the University of Toronto Scarborough, who specializes in planet and solar system formation, said in a statement.

According to researchers, 'Oumuamua likely came from a binary star system with a hot, giant star, since such star systems would likely have more number of rocky objects within. Researchers also believe the interstellar asteroid may have been ejected when planets began forming in the system.

When it was first spotted, researchers assumed it was a comet. However, they soon discovered that 'Oumuamua didn’t display any comet-like activity as it approached the sun, which led them to reclassify it as an asteroid.

The alien asteroid was seen hurtling across space at incredible speeds and at its closest, was around 33,000,000 km from Earth. Its speed, trajectory and hyperbolic orbit also helped scientists ascertain that it came from outside the solar system. According to Jackson, 'Oumuamua’s orbit has the highest “eccentricity” ever seen in any object observed passing through our solar system.

However, there are still many mysterious aspects about 'Oumuamua that are yet to be unmasked. Scientists like Jackson also believe that the interstellar asteroid may provide clues to how planets are formed in other star systems.

“The same way we use comets to better understand planet formation in our own Solar System, maybe this curious object can tell us more about how planets form in other systems,” Jackson said.

The new study was published in the Monthly Notices of the Royal Astronomical Society.