The mysterious stranger at the edge of our solar system may not be a planet after all. More importantly, it might not be a friendly stranger.
In fact, the "object" that has long beguiled scientists — dubbed Planet Nine — may actually be a cluster of asteroids, according to new research. What's more, those asteroids could be flinging comets at us, maybe even playing a role in the disappearance of the dinosaurs.
That's a heavy accusation to level against something we have yet to prove exists. But researchers at the University of Colorado Boulder suggest the space oddities attributed to Planet Nine — like strange gravitational effects and rogue planetary bodies — may actually be caused by jostling asteroids.
Although they have yet to catch sight of it, scientists have long-suspected a ninth planet may be lurking beyond Neptune. Perhaps the most tantalizing suggestion of its existence is Sedna, one of several not-quite-planets that exist beyond Neptune. Considered a "detached object," Sedna takes around 11,000 years to work its way around our sun. That epic orbit keeps Sedna and other detached orbits far outside of the inner solar system's planet club.
So how do these bodies stray so far from the pack?
Cue the ninth planet theory: Another planet — and a very big one at that — has been pulling Sedna's strings with its own gravitational pull.
But Colorado researchers suggest asteroids bunched together could use the same modus operandi. In the smash-up derby at the outer limits of the solar system, passing planets like Sedna could get bumped here and there, causing their orbits to go extremely wide.
And then there's the possibility of clustered asteroids exerting their own gravity on nearby objects.
"There are so many of these bodies out there. What does their collective gravity do?" Ann-Marie Madigan of the University of Colorado, told CU Boulder Today. "We can solve a lot of these problems by just taking into account that question."
In a June 4 presentation at the 232nd meeting of the American Astronomical Society, the research team suggested all that bumping leads to detached orbits for minor planets like Sedna.
"You see a pileup of the orbits of smaller objects to one side of the sun," lead research author Jacob Fleisig noted. "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."
So how do happenings as far flung as the outer solar system affect life here on Earth? Well, possibly very dramatically.
These swirling, jostling asteroids may occasionally draw in a comet from the edge of our system — and essentially pea shoot it in our direction.
Every now and then, one of those comets comes perilously close to our own backyard. And 66 million years ago, one may have hit the mark much to the eternal chagrin of resident dinosaurs.
"While we're not able to say that this pattern killed the dinosaurs," Fleisig noted, "It's tantalizing."
But aside from occasionally meddling in Earthly affairs, this chaos-causing rock cluster may also be poised to turn textbooks on their head.
"The picture we draw of the outer solar system in textbooks may have to change," Madigan explained in CU Boulder Today. "There's a lot more stuff out there than we once thought, which is really cool."