Sometimes reading a headline you didn’t ever expect to see just brightens your entire day. You can take a breath, smile and realize everything you knew as a child is coming back, and all is right with the world.
I’m talking, of course, about the news that Pluto is no longer a dwarf planet.
To be considered a planet, three rules have to be taken into consideration: It must orbit around the sun, be spherical and be the biggest body in its orbit. Pluto met the first two, but the dwarf planet Eris cuts right through Pluto’s orbit and is bigger by just 27 percent.
Upon the discovery, the International Space Union took Eris into consideration and declared Pluto a dwarf planet in 2006, when the three rules to what defines a planet were made. Now, the Harvard-Smithsonian Center for Astrophysics has decided to revisit what makes a planet.
They invited specialists Owen Gingerich, chair of the International Astronomical Union planet definition committee; Gareth Williams, associate director of the Minor Planet Center; and Dimitar Sasselov, director of the Harvard Origins of Life Initiative to explain what makes a planet.
Gingerich said, “A planet is a culturally defined word that changes over time.”
Williams defended the IAU’s definition of a planet, rejecting Pluto as a planet.
With a 2-1 majority in favor of Pluto, the audience was asked to vote for Pluto’s planetary status by choosing which definition of a planet they thought worked best. Sasselov’s definition won over the other two, and Pluto has regained the title of planet.
Of course, a “spherical lump” is not the new definition of planet, but we can welcome Pluto back with open arms.
This vote doesn’t really hold much weight in the scientific community, so Pluto has not been officially renamed as a planet yet. But all of its supporters are waiting hopefully, for the first time in eight years, that it might be.
However, the debate isn’t over. Principal investigator Alan Stern said the public is better suited to decide what makes a planet over astronomers.
The IAU had no ground to lay out the rules for what makes a planet and shouldn’t have pretended to have the expertise to enter this debate. It’s a matter for planetary scientists, not astronomers.
Growing up with Pluto as a planet and then being told as a young adult it wasn’t a planet anymore didn’t have too much effect on me. Of course it was a planet, who are you kidding? Every kid in this generation knows that.
Essentially, I refused to believe it, but eight years of non-planetary status can wear one down, and eventually it was accepted as fact. The hope Pluto would join us again never died, though. As of Sept. 18, Pluto once again has a fighting chance.
Email Amanda Little at amanda.little@cardinalpointsonline.com.
