The New Dwarf Planet And The Arizona Daily Star

It’s possible to be right about something and still manage to get it completely wrong. For evidence of this fascinating phenomenon, let’s look at yesterdays’s front page stories on the Arizona Daily Star. “Say hello to huge, new planet — or not:”

Forget Pluto.

A dwarf planet recently discovered at the far edge of our solar system adds evidence for the existence of a much larger body, possibly 10 times the size of Earth, orbiting far from the sun but still in our solar system.

If astronomers can track it down, we could become a nine-planet solar system once again.

The planet is theoretical for now, inferred from the influence it seems to have on this new dwarf planet and others in its vicinity.

To understand how the Daily Star got it wrong, even though the article is technically correct, we need to look at how this story is constructed.

First, what’s the actual noteworthy piece of information? A new dwarf planet was discovered in the solar system. Neat! Despite how many people denigrate dwarf planets ever since Pluto’s demotion (even the terminology looks down on dwarf planets), I think that dwarf planets are pretty cool.

For one thing, they add a lot more ladies to our celestial neighborhood. Sedna, Eris, and Haumea bring three more goddesses to the ranks of the celestial bodies, not to mention dwarf planet Ceres in the asteroid belt. Sure, it’d be nice if we could name a few more full fledged planets after goddesses to even out the decidedly masculine solar system, but that ship may have already sailed. Maybe the first named exoplanet can be a goddess?

So the news article is about the discovery of a new dwarf planet. Very cool. The problem is that the article and the headline both make it sound like this dwarf planet is somehow confirming the existence of a huge planet out there in the black, which is something that’s been speculated on for years. From the same Daily Star article:

What’s most interesting to the astronomers is that previously found objects and some they have since discovered are equally eccentric.

They point to the influence of a giant planet that perturbed the orbits of the objects being found and then either flew off into space — or is still hiding out there somewhere.

“The evidence for it is circumstantial,” Sheppard said in a phone interview from Chile, where he is observing again on the Blanco DECam at the Cerro Tololo International Observatory.

Bold emphasis is mine. Despite the general tone of the article, despite the headline, despite the fact that the discovery of a dwarf planet is still cool science news, the article insists on making it seem like we’re actually on the verge of discovering Planet X even though the only real information on that point is a single quote that describes the evidence as circumstantial.

Here’s what Phil Plait, he of the legendary Bad Astronomy blog has to say about the possibility of a large planet lurking out there:

It’s possible that a bigger object—a proper planet-sized thing—could be out there in the Oort cloud, hundreds of AU away from the Sun, that could be affecting the orbits of these objects. If it were a giant planet like Jupiter or Saturn we would have detected it by now, so it would have to be something smaller and colder. An object the size of the Earth (or even somewhat bigger) would fit the bill. It’s an idea that’s been around for a while now.

Mind you, the evidence here is pretty thin, and as much as I’d love for there to be another planet lurking out there for us to find and study, we just don’t have enough data here to say anything either way. It’s small number statistics; we’ve found two objects with odd orbits, but it could be coincidence. We need to find a lot more OCOs like Sedna and VP113 so that the gaps in our understanding of their orbits can be filled in.