Pluto is Pluto. And that is enough
Pity poor Pluto. The once full- fledged planet has inspired many an earthly tribute, from a radioactive substance ( Plutonium is number 94 on the Table of Elements) to a colourful canine in the Disney cast of characters.
But Pluto’s status suffered a major blow a few years ago.
In 2006, the International Astronomical Union shocked the world when it announced Pluto would no longer be considered a planet. It is, they said, a dwarf planet. That left us with only eight bona fide planets in our solar system, a fact that must have had Gustav Holst, composer of “The Nine Planets,” spinning in his grave.
It’s true that Pluto was always the least understood among its planetary siblings. In fact, its existence was only confirmed very late in the game.
The man who discovered it was American astronomer Clyde Tombaugh, who was hired by the Lowell Observatory in 1929. Uranus and Neptune had already been discovered in 1781 and 1846, respectively, but there were still discrepancies in the movement of the latter that suggest a ninth body beyond.
Tombaugh spent eons pouring over photographic images. In February 1930, he finally noticed an object moving across the field of a pair of images taken a month beforehand. After verifying the finding, the Lowell Observatory officially announced the discovery of the ninth planet on March 13.
Fortunately, Tombaugh died in 1997, and did not witness the demotion of his beloved Pluto.
The downgrading to dwarf status — and who would dare suggest dwarf planets are not full, participating members of planet society anyway? — just happened to occur after the launch of New Horizons, a Pluto probe that has started transmitting startling photos back to Earth within the past few days.
Earlier this week, the NASA probe captured its latest snapshot of the ninth rock from the sun from less than eight million kilometres away.
It’s now less than six million kilometres away, and is expected to make a historic flyby next week. Here’s the funny part, though. Excited by this first close encounter of a distant cousin, a campaign to reinstate Pluto’s status has gained new vigour.
And Alan Stern, principal investigator with the mission, is right on board.
He thinks once the public starts seeing pictures of the little tyke, they’ll want to call it a planet again. And if it doesn’t fit the existing definition, well, just change the definition.
It’s all a little silly, really. Pluto is even smaller than our moon. In fact, there are four other dwarf planets in our system: Ceres, Haumea, Makemake and Eris. Should we promote them all to planets?
Perhaps we should just stop obsessing over terminology altogether. Pluto is Pluto. And that is enough.
As for Tombaugh — the probe is carrying a small portion of the late astronomer’s ashes on its journey.
Now that is truly cosmic.