The New Horizons probe, which NASA launched nearly 10 years ago to observe Pluto up close, sent back some incredible of the planet. But wait, is it a planet, or not?
When New Horizons left Earth in January 2006, Pluto was officially a member of the planet club along with Mercury, Venus, our lovely green home, Mars, Jupiter, Saturn, Uranus, and Neptune. By the end of that year, the powers that be decided to strip Pluto of its planet-hood. Instead, they determined that the tiny, cold, barren sphere should be relegated to the status of dwarf planet.
Now that we have these beautiful, detailed, never-before-seen images of Pluto, many are wondering if we’ve made a mistake. Should we bring Pluto back into the fold of true planets? Or is all of this just semantics?
Here’s a little backstory to explain how we got to the present conundrum. Back in 1930, when Pluto was officially discovered, scientists did not have the equipment we enjoy using 85 years later. They guessed that Pluto was roughly the same size as Earth. While they were wrong, their assumption made it reasonable that Pluto should be the ninth planet circling out sun.
As the years went on, and technology improved, researchers found that Pluto’s mass was much smaller than Earth’s. By 2006, it was determined that earth was 459 times larger than Pluto. Pluto was also swimming amidst a lot of junk—not in a cleared-put area like other planets.
But here’s what really did in Pluto’s planet status: In 2005, astronomers found an object near Neptune which they named Eris. This little planet also orbits the sun—and it happens to be 27 times the mass of Pluto.
So the dilemma was this: make Eris the 10th planet, or make Pluto a non-planet. Officials decided on the latter.
While there are some tangible implications to the debate, such as funding for planetary research, does it really matter what we think Pluto is? It’s out there, it’s circling the sun, it’s round, and we now have a greater appreciation for its beauty thanks to New Horizons. Yes, there are moons and other objects larger than Pluto, but that’s not the point.
Regardless of what we call objects in the sky, they deserve our attention and our awe. Is Pluto a planet, a dwarf planet, or something else?
Who cares. Let’s find out as much as we can about it, regardless of its classification.