Science Sunday: Debate Continues Over The Planet Formerly Known As Pluto

HUBBLE IMAGES OF THE CHANGING FACE OF PLUTO

It has been nearly four years since the infamous decision by the International Astronomical Union to demote Pluto to "minor planet" status, and while I'm all for integrity in astronomy, I've been troubled about all those solar system mobiles hanging in classrooms the world over. Didn't the astronomers who delisted the ninth planet consider the consequences of Edna Krabbapel and other teachers having to take a scissors to Pluto? Wouldn't their mobiles get all lopsided, or something?

Now even some of those curmudgeonly astronomers are having second thoughts about Pluto and the debate over whether it should be relisted rages on genteelly. As opposed to the hammer-and-tongs warfare over global warming, stem cell research and other scientific hot buttons.

Rick Moran covers this debate . . . well, genteelly over at his inaptly named Right Wing Nuthouse. Rick sort of has has a personal stake in the debate because his adopted hometown of Streater, Illinois, was the birthplace of Clyde Tombaugh (above, right), who discovered Pluto back in 1930, and is the recipient of major face time in "The Pluto Files," a terrific new Nova documentary which can be seen on your local PBS station. Yeah, the same PBS that real right wingers would like starve of funding.

The documentary is hosted by the incomparable Neil deGrasse Tyson (above, left), the director of New York's Hayden Planetarium, whom Rick notes has assumed the title "The People's Scientist" that had been vacant since Carl Sagan left this mortal coil in 1996. Those right wingers didn't much like Sagan either, but that's another story.

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Tombaugh's discovery of the dwarf planet . . . er, minor planet is among my astronomical favorites.

Pluto's existence had been predicted by astronomers Percival Lowell (right) and William Pickering, who dubbed it Planet X. It fell to young Tombaugh to perform a systematic search for the trans-Neptunian planet. Using the 13-inch astrograph (below, left), a camera telescope, at the Lowell Observatory near Flagstaff, Arizona, he took photographs of the same section of sky several nights apart in January 1930. He then used a device known as a blink comparator to compare the different images.

When Tombaugh shifted between two images, a moving object such as a planet would appear to jump from one position to another, while the more distant objects such as stars would appear stationary. He noticed such a moving object in his search near the place predicted by Lowell, and subsequent observations showed it to have an orbit beyond that of Neptune.

Planet X was officially designated the ninth planet on February 18 of that year. It was named Pluto on May 30, 1930 at the suggestion of Venetia Burney (below, right), a precocious 11-year-old English school girl, who won out over other suggestions by noting that Pluto was the Roman god of the underworld because he was able to make himself invisible and because Percival Lowell's initials "PL" formed the first two letters.

Burney, who died in 2009, lived to see "her" planet hit a rough patch.

Following the discovery of the Kuiper Belt in the early 1990s, Pluto began to be seen not as a planet orbiting by its lonesome but as the largest of a group of icy bodies in that region of space. When it was subsequently determined that one such body was larger than Pluto, the IAU reclassified the planet and grouped it with two similarly sized "dwarf planets."

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Tyson reenters our story owing to the fact that in 2001 he had set off a solar spit storm by removing Pluto from the display of planets at the Hayden because he was convinced it was not a true planet but merely a "cosmic body." I have a sneaking suspicion that one of the reasons that Tyson and other people who stay up all night peering into the heavens got all grumpy over Pluto is that Walt Disney had named his goofy cartoon dog after it. But that also is another story.