Is There Really a Planet X?

Have you heard there’s a giant planet in the Solar System headed straight towards Earth?

At some point in the next few months or years, this thing is going to crash into Earth or flip our poles, or push us out of our orbit, or some other horrible civilization destroying disaster.

Are these rumours true?

Is there a Planet X on a collision course with Earth?

Unlike some of the answers science gives us, where we need to give a vague and nuanced answers, like yes AND no, or Maybe, well, it depends…

I’m glad to give a straight answer: No.

Any large object moving towards the inner Solar System would be one of the brightest objects in the night sky. It would mess up the orbits of the other planets and asteroids that astronomers carefully observe every night.

There are millions of amateur astronomers taking high quality images of the night sky. If something was out there, they’d see it.

These rumours have been popping up on the internet for more than a decade now, and I’m sure we’ll still be debunking them decades from now.

What people are calling Planet X, or Nibiru, or Wormwood, or whatever doesn’t exist. But is it possible that there are large, undiscovered objects out in the furthest reaches of Solar System?

Sure.

Astronomers have been searching for Planet X for more than a hundred years. In the 1840s, the French mathematician Urbain Le Verrier calculated that another large planet must be perturbing the orbit of Uranus. He predicted the location where this planet would be, and then German astronomer Johann Gottfried Galle used those coordinates to discover Neptune right where Le Verrier predicted.

The famed astronomer Percival Lowell died searching for the next planet in the Solar System, but he made a few calculations about where it might be found.

A young Clyde Tombaugh with one of his famous homemade telescopes. (Credit : NASA/GSFC).
A young Clyde Tombaugh with one of his famous homemade telescopes. (Credit : NASA/GSFC).
And in 1930, Clyde William Tombaugh successfully discovered Pluto in one of the locations predicted by Lowell.

Astronomers continued searching for additional large objects, but it wasn’t until 2005 that another object the size of Pluto was finally discovered by Mike Brown and his team from Caltech: Eris. Brown and his team also turned up several other large icy objects in the Kuiper Belt; many of which have been designated dwarf planets.

We haven’t discovered any other large objects yet, but there might be clues that they’re out there.

In 2012, the Brazilian astronomer Rodney Gomes calculated the orbits of objects in the Kuiper Belt and found irregularities in the orbits of 6 objects. This suggests that a larger object is further out, tugging at their orbits. It could be a Mars-sized object 8.5 billion km away, or a Neptune-sized object 225 billion km away.

A false-color, visible-light image of Comet ISON taken with Hubble's Wide Field Camera 3. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
A false-color, visible-light image of Comet ISON taken with Hubble’s Wide Field Camera 3. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
There’s another region at the edge of the Solar System called the Oort Cloud. This is the source of the long-period comets that occasionally visit the inner Solar System. It’s possible that large planets are perturbing the orbits of comets with their gravity, nudging these comets in our direction.

So, feel free to ignore every single scary video and website that says an encounter with Planet X is coming.

And use that time you saved from worrying, and use it to appreciate the amazing discoveries being made in space and astronomy every day.