Well, the intriguing possibilities affecting the likelihood of a mysterious companion in our Solar System continue to blossom.
First, the actions of comets suggested that there may be a large “Planet X” named Tyche beyond the Oort Cloud. Then, we discovered planets around distant stars with highly elliptical, highly inclined orbits, giving us more potential places (oblique orbits) to look for distant, cool companions in our own system.
Now, SwRI researcher David Nesvorny recently published research indicating that our Solar System likely did have another giant planet in its youth that was flung into space as the planets matured and settled into their current orbits.
Why? Well, as it turns out, computer modeling of star systems with only four giant planets, (read: Jupiter, Saturn, Uranus, and Neptune,) doesn’t tend to settle into a Solar System that looks anything like our own. However, adding a fifth, giant icy world into the primordial mix appears to generate systems like ours, though this Planet X is ejected into interstellar space in the process.
So, according to this new research, there may indeed have been a Planet X in our planetary past, though not one that could ever return to fulfill doomsday prophesies.
Might the cold, shadowy deep beyond the prying eyes of our best infrared telescopes conceal large worlds awaiting the heady thrill of human exploration? Research continues to tease us with the possibility.
I for one believe our star system has big surprises yet in store. Time will tell.