Collective gravity, not Planet Nine, may explain the orbits of "detached objects"

James Marshall
June 7, 2018

It's their collective gravity acting in concert that solves numerous puzzles posed thus far, Ann-Marie Madigan, a C.U. Boulder assistant professor and also author of the study, said. This minor planet orbits Earth's sun at a distance of 8 billion miles but appears separated from the rest of the solar system. "We can solve a lot of these problems by just taking into account that question".

Scientists quantified the orbits of Sedna and its ilk may result from these bodies jostling against each other and space debris in the outer solar system.

The orbits of these detached objects clustered together in a way that didn't seem random - but a huge planet way out beyond Pluto, many astronomers agreed, could have tugged them into the observed configuration. However, a new study exploring the interaction between icy trans-Neptunian objects sitting in the outer parts of our solar system hints that the collective gravity from these objects, and not Planet Nine, might be responsible for the unusual orbits of the detached objects. For example, there's still "clustering in pomega", which Madigan described as the odd fact that the orbits of the detached objects all tilt the same way.

As Bennett reports, the search for Planet 9 began in 2014 with the publication of study showing that two objects that orbit the sun beyond Neptune (Sedna and 2012 VP113) had nearly circular orbits.

"They are what's causing this detachment, and not an unseen ninth planet", study lead author Jacob Fleisig, an undergraduate astrophysicist at the university, said during the conference. However, searches for the planet over the last two years have been unsuccessful.

She added: "The picture we have in our head is a lot of little moons floating around the solar system, interacting with comets".

According to the researchers' simulations, the TNOs move like hands on a clock, with the most massive objects moving slowly, like the hour hand, and the smaller ones ticking along quickly, like the minute hand.

"Planet Nine explains this really well, and we do not", admits Madigan.

'These orbits crash into the bigger body, and what happens is those interactions will change its orbit from an oval shape to a more circular shape'.

In the latest study, presented this week at a meeting of the American Astronomical Society, astronomers looked at new models depicting how the massive swarm of objects that make up the Kuiper Belt orbit the sun.

This theory matches a 2012 finding showing the larger a detached TNO becomes, the more distant its orbit gets from the Sun. If these gravity bumps are strong enough to push big objects like Sedna away from the sun, then, theoretically, they could also hurl comets and asteroids toward the inner solar system, targeting the unsuspecting rocky planets.

Remarkably, these relatively insignificant objects may also be culpable in the extinction of the dinosaurs.

"While we're not able to say that this pattern killed the dinosaurs", Fleisig said, "it's tantalizing".

It's not impossible one of these caused the collision which wiped out the dinosaurs, the researchers said.

Other reports by Click Lancashire

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