The same thought occurred to me --- if there is a planet, its orbit is important.
There are comets out there with elongated, eccentric orbits that take them far outside the solar system, such that it takes decades or even centuries to complete a single orbit. It's only when they approach the sun that they become visible. One of them collided with Jupiter last year, as I recall.
What if there's a planet out there whose orbit crosses ours? Could be trouble.
Planet Nibiru! home of our alien creator gods the Anuunaki.
Last time they visited the Mesopotamians many thousands of years ago they created us, their slave race, to mine gold.
The sky gods will return, yea verily!