Actually we’ve got 53 planets

Xena and GabrielleThe man who discovered the IAU’s recommended new 12th planet reckons the organisation can’t count.

Dr Mike Brown says their proposed definition of a planet means there are now at least 53 of the worlds, not nine or twelve.

Brown, whose own find, 2003 UB313, has been nicknamed Xena, told me that 44 recently discovered icy worlds beyond Neptune fit the IAU’s new criteria. There are likely to be hundreds more.

As I revealed earlier, Brown, of the California Institute of Technology, agreed with me that it was “crazy” to exclude the Moon from being a planet. He added: “Also strange is that they seem to have a hard time counting. I come up with 53 planets.”

You can read Brown’s interesting take on it all here. He says: “Astronomers have needed a good scientific definition of the word ‘planet’ for many years now and this one works well for scientists. It doesn’t, however, work terribly well for the rest of the world.

“The solution is the one that should have happened long ago: a divorce of the scientific term ‘planet’ for the cultural term ‘planet.’ No one expects school children to name 53 planets. If I were a schoolteacher, I would teach perhaps 10 and then say “scientists consider many more things to be planets too” and use that opportunity to talk about how much more there is in the solar system.”

The image of new planet Xena, revealing it has a moon, nicknamed Gabrielle, was taken at the Keck Observatory, Hawaii.

Paul Sutherland

Paul Sutherland

I have been a professional journalist for nearly 40 years. I write regularly for science magazines including BBC Sky at Night magazine, BBC Focus, Astronomy Now and Popular Astronomy. I have also authored three books on astronomy and contributed to others.
Paul Sutherland

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Paul Sutherland

I have been a professional journalist for nearly 40 years. I write regularly for science magazines including BBC Sky at Night magazine, BBC Focus, Astronomy Now and Popular Astronomy. I have also authored three books on astronomy and contributed to others.

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