It appears the debate is hotting-up again and that Pluto may return to its status as the ninth planet. One thing for sure, My “Pluto 1830-2006, (R)evolve (I)n (P)eace” T-shirt is destined to a holding pattern in my closet while this gets sorted.
As a child, I, like many others, was taught the mnemonic device “My Very Excellent Mother Just Sent Us Nine Pizzas” in order to remember the order of the nine planets. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. It helped, and I never struggled with them again. That all went to hell, in 2006 when Neil DeGrasse Tyson among others rubbished the little planets planetary aspirations it thought it was living up to ever since its discover by Clyde Tombaugh in 1930.
Pluto ran afoul of the International Astronomical Union, the group that names planetary bodies, in 2006 after the group suggested that a planet must: Orbit the sun, is round or nearly round, and has cleared the neighborhood around its orbit.
But because of its size, or perhaps its just well-mannered Pluto was shunned as a planet by rule number three as it hasn’t knocked all the space rocks out of its orbit.
Harvard wants Pluto as planet
But now Owen Gingerich, a Harvard science historian, and chair of the IAU planet definition committee, but he seemingly wants Pluto back and stated at a forum last month that Pluto was a planet because, ”a planet is a culturally defined word that changes over time.”
Following the forum, those in attendance voted, and if that vote would have been at all binding, Pluto would have been immediately returned as a planet.
Gingerich and those in attendance at Harvard aren’t alone. Alan Stern, the principal investigator for the New Horizons spacecraft, which was sent to Pluto believes Pluto’s distance from the sun led to its planetary demise.
“In fact, if you put Earth where Pluto is, it would be excluded!” Stern said. “Any definition of planethood that excludes Earth, in any circumstance, is deeply flawed. After all, if there is any object everyone agrees is a planet, it’s Earth.”
“I think the public is better suited to this than astronomers, at least,” Stern said. “The IAU should never have pretended to have the expertise to enter into this debate. It’s a matter for planetary scientists, not astronomers.”
Can’t we all get along?
“This is really about a revolution in planetary science,” Stern said. “We’re seeing that what we used to know about the number and variety of planets was very data limited until the mid- to late 1990s. Now we know that there are lots of types of planets.”
He almost sounds like the Martin Luther King, Jr. of planetary equality.
Stern has a lot on his plate right now with the imminent arrival of New Horizons at Pluto in July 2015. It may not end the debate but Stern said the mission is “going to be mind-blowing.”
On the other hand, once pictures begin arriving back on Earth, the debate might finally reach its conclusion.
The arrival of New Horizons is not guaranteed and Stern promised “seven weeks of suspense,” as New Horizons enters an asteroid field prior to reaching Pluto.