While much of the effort involved in tracking down the rumored ‘Planet Nine’ has focused on exploring the outer reaches of our solar system, some researchers believe that there may in fact have once been a sizable planet much closer to home, somewhere between the orbits of Uranus and Saturn.
This ancient, icy world was likely ejected from the solar system billions of years ago.
To determine this, scientists created thousands of simulations to rewind the clock and recreate the orbits of the planets – and in particular the gas giants – to examine how they evolved over time.
“We now know that there are thousands of planetary systems in our Milky Way galaxy alone,” said study lead author Matt Clement from the Carnegie Institution for Science.
“But it turns out that the arrangement of planets in our own solar system is highly unusual, so we are using models to reverse engineer and replicate its formative processes.”
“This is a bit like trying to figure out what happened in a car crash after the fact – how fast were the cars going, in what directions, and so on.”
The researchers also found that the positions of Uranus and Neptune were altered by the Kuiper Belt.
“This indicates that while our solar system is a bit of an oddball, it wasn’t always the case,” said Clement.