Irregular Webcomic! #1424

Howard Phillips Lovecraft's short story The Whisperer in Darkness is, like many of his works, a chilling science fiction horror story. It introduces the fictional beings known as the Mi-go, who, as Terry describes, come from the planet Yuggoth.

Lovecraft set up Yuggoth as a mysterious dark planet beyond the edge of the solar system - which up until 1930 was considered to end at the last known planet, Neptune. The discovery of Pluto in 1930 gave us a ninth planet, and served as one of the inspirations for The Whisperer in Darkness, as Lovecraft sets up the mystery of an unidentified ninth planet early in the story, and then postulates that the recent discovery of Pluto perhaps confirms the incredible horrors that he has described in the story up to that point.

The Mi-go themselves are basically as Terry describes them. They are strange fungoid beings with hard crustacean-like carapaces, large bat-like wings, a strange fleshy appendage covered in antennae instead of a head, and so on. Which is kind of odd, given that Lovecraft explicitly identifies them with the Migou, which is the Tibetan name for the yeti. As far as I know, no traditional Himalayan accounts of the yeti refer to them as fungus-beings from Pluto with wings and exoskeletons.

Someone must be hiding something...

Anyway, since 1930 we've lived in a solar system containing nine planets. No doubt almost everyone reading this learnt at school that there are nine planets in our solar system. Of course, what is a planet is a matter of definition, and this year (2006) the International Astronomical Union decided that the definition of what was and what was not a planet needed to revisited, following the recent discoveries of several Pluto-like objects orbiting in the deep solar system. The crunch came with the discovery of Eris, which is larger than Pluto.

It has become clear that Pluto is not unique in any sense. There is a large population of roughly Pluto-sized bodies of similar composition orbiting the Sun at similar distances. The options were either:

Call all these things planets, since they are like Pluto and Pluto has been called a planet for over 75 years. This would mean we would now have something like a dozen known planets, and the certain knowledge that there are dozens if not hundreds of other planets that we haven't yet discovered.
Don't call these things planets, but leave Pluto as a planet because of tradition, leaving us with our familiar nine planets.
Change the meaning of "planet" to exclude Pluto, Eris, and all the hundreds of other things out there that are just like them.

Each option has advantages, disadvantages, adherents, and detractors. A large fraction, perhaps even a majority, of the general public held a strong emotional attachment to Pluto being a planet. This is only natural, as nobody likes being told that what they learnt at school was wrong. That means that a lot of people supported either option 1 or 2 above.

From a scientific viewpoint, option 1 is undesirable, because it changes what was considered a fundamental property of planets - that they are relatively rare objects in a solar system, of primary importance after the Sun itself. Whatever way you look at it, Pluto, Eris, and their band of friends are not of similar importance to solar system studies as the big eight planets. They form a little group of objects of their own, known as Kuiper Belt Objects. Or not such a little group; over 800 are known so far, and many thousands more are expected to be out there.

Option 2 is incompatible with a consistent set of definitions that can apply to all objects. You can't say that all oranges are oranges, except for this one, which is not different from any other orange, except that we call it an apple. Well, you can, but it doesn't make much sense.

Which left option 3. The unpopular option.

So the IAU redefined what a planet is. Pluto is no longer considered a planet. We have eight planets again. And there are quite a few people who are actively angry about that decision.

The Mi-go are probably among them.

2016-08-02 Rerun commentary: Given it's now almost ten years since this comic was first published, it's quite possible that there are now people reading it who learnt at school that there are eight planets and that Pluto is a member of the classes of dwarf planets and Kuiper belt objects.

Now that I think about it, I've taught kids that myself, during some of my semi-regular visits to a local primary school as part of the CSIRO Scientists in Schools program (which I've mentioned a few times before).