A quick check of my online horoscope on Wednesday morning helped allay the fear that had kept me awake most of the previous night: the planets were still favourably aligned for my career, health and love life.
And so, indirectly, Pluto was safe. Because surely someone as experienced at reading the heavens as the muse behind Astrology.com (‘the leading astrology site since 1995â€) would have noticed and made some mention if the smallest planet had lost its planethood.
What the oracle didn’t see, and which might undermine my faith in its predictions, was that the exclusive club of nine has been extended to 12.
Astronomers of the International Astronomical Union (IAU, the ones that perform the more prosaic duty of studying the physical properties of heavenly bodies), meeting in Prague, are considering a recommendation from a committee charged with defining the term ‘planetâ€.
The conference will make a final decision on August 24, but seems likely to go with the suggestion, formally put forward on Wednesday, that there be 12 planets: the nine that have been accepted since 1930 (when Pluto joined), plus Ceres, Charon and Xena.
Ceres is the largest known asteroid in the solar system, Charon is Pluto’s moon. But it’s not all good news for Pluto-lovers. At the same time as elevating Charon, the infernal ferryman, to the same rank as the king of the underworld, the IAU has politely demoted both to the status of Mickey Mouse’s dog. For, although there will be 12 planets, only eight will be ‘classical planets that dominate the systemâ€, while Pluto will head ‘a new and growing category†called Plutons.
Xena, the warrior princess of TV series fame, is better known to the scientific community as 2003 UB313, and is the main reason why the issue of what constitutes a planet came to a head.
In 2003, Michael Brown, a scientist at the California Institute of Technology, spotted Xena in the Kuiper Belt, a band of orbiting matter in the outer solar system beyond Neptune, so named by people tracking a particularly hard-hit six from former Proteas batsman Adrian Kuiper. Okay, so I made up that last bit.
Brown announced that 2003 UB313 not only had the same properÂties as Pluto — an almost round object taking more than 200 years to trundle in an eccentric orbit around the sun — it is also nearly one-and-a-half times bigger, making it the largest object discovered in the solar system since Neptune. Others have corroborated his findings, which makes Xena’s entry into the big league more legitimate than that of Pluto itself.
When Clyde Tombaugh and his peers at the Lowell Observatory in Arizona announced their discovery of Pluto in 1930, they said it was several times bigger than Earth. ‘Their public relations was great, but their astronomy was lacking a bit,†Brian Marsden, director of the IAU’s Minor Planet Centre in Cambridge, Massachusetts, told The Guardian.
The IAU has accepted Brown’s science, but not his nickname. Xena does not come from classical mythology and so does not fit in with the way heavenly bodies are named. But the Union has cleverly deferred assigning a new name for a couple of months — presumably to see if there is a worldwide campaign to keep ‘Xenaâ€, much as there has been to save Pluto.
Spare a thought for Pallas, Juno and Vesta, too. The second to fourth-biggest asteroids were recognised, along with Ceres, as planets from the early 19th century until the discovery of Neptune in 1846. Now their only hope is to become Plutons.