London: Encounter with a planet beyond Pluto — the so-called Planet Nine — millions of years ago might have separated and pushed a binary asteroid to their current orbits, says a study.
These two distant objects starting as a pair orbiting one another, became gradually separated in their orbits because they made an approach to a much more massive object at a particular moment in time, according to the study published in the journal Monthly Notices of the Royal Astronomical Society.
Making the first spectroscopic observations of the two distant objects — 2004 VN112 and 2013 RF98 — the scientists found that their orbits are almost identical and the poles of the orbits are separated by a very small angle.
This suggest a common origin, and their present-day orbits could be the result of a past interaction with the hypothetical Planet Nine, according to the team.
“The similar spectral gradients observed for the pair 2004 VN112 – 2013 RF98 suggests a common physical origin,” explained first author of the paper Julia de Leon, an astrophysicist at the Instituto de Astrofísica de Canarias (IAC) in Spain.
“We are proposing the possibility that they were previously a binary asteroid which became unbound during an encounter with a more massive object,” de Leon said.
To validate this hypothesis, the team performed thousands of numerical simulations to see how the poles of the orbits would separate as time went on.
The results of these simulations suggest that a possible Planet Nine, with a mass of between 10 and 20 Earth masses orbiting the sun at a distance between 300 and 600 astronomical unit (AU) could have deviated the pair 2004 VN112 – 2013 RF98 around five and 10 million years ago. One astronomical unit equals to approximately 150 million kilometres.