CNET también está disponible en español.

Ir a español

Don't show this again

Christmas Gift Guide

Say that to his face

Because technically ALL dwarf planets should be planets

Because Pluto fits two out of three requirements ... and the third requirement is kinda weak

Because, seriously, it's just like Earth

Because: Tradition

Because barely 2% of the IAU actually voted to de-planetize Pluto

Because Pluto is still largely undiscovered

Because the head of NASA still calls it a planet

Pluto, that distant heavenly body, is on every Earthling's lips this week, thanks to new pictures sent by the New Horizons spacecraft. And with those images, and old wound has been opened: The demoting of Pluto from "planet" to "dwarf planet" status in 2006.

Plenty of folks still count Pluto as a planet. And they have their reasons. For starters, New Horizons has confirmed that Pluto has mountains and water. The International Astronomical Union doesn't consider such traits when deciding what makes a planet ... but, given that a certain third rock from the sun also has mountains and water, maybe it should reconsider.

Here are even more reasons to count Pluto among the Big Nine ...

Caption by / Photo by NASA

Of the known trans-Neptunian objects, Pluto is among a subgroup that includes planet-like Ceres, Eris (which is bigger than Pluto) and Makemake. Many scientists argue that we should open up the floodgates, at least a little, and let a few more of those bodies into the official planet club.

Caption by / Photo by NASA

To be a planet, a body needs to meet certain requirements, according to the International Astronomical Union.

Pluto orbits around the sun: check. Pluto has a round shape: check. But it hasn’t cleared its orbit of debris. Strike! Wait a minute, though: According to scientists, Jupiter and Earth technically violate rule No. 3 as well. And because Pluto is furthest from the sun, and dwells in a rotten neighborhood filled of debris, it gets the worst deal of them all. So cut Pluto some slack, International Astronomical Union!

Caption by / Photo by Michael Brown/Getty Images

Pluto has its own moon, known as Charon, and it’s geologically active, meaning its filled with things our planet is filled with, including rocks and ice. Again, the IAU cares nothing for such definitions, but its definition is extremely narrow.

Caption by / Photo by IAU/AFP/Getty Images

The word "planet" had a broader usage for a millennia before a group of astronomers narrowed down its meaning.

Caption by / Photo by Michal Cizek/AFP/Getty Images

Out of around 10,000 internationally registered members of the Astronomical Union, only 237 members voted to reclassify Pluto as a “dwarf planet,” while 157 voted against the demoting in the General Assembly in Prague. The other 9,500-plus members weren’t even there!

Caption by / Photo by Michal Cizek/AFP/Getty Images

The New Horizons mission will be the first to truly explore Pluto, whereas the other planets within our solar system have already been heavily researched. We still don’t know how Pluto formed, what its atmosphere is made of, if it has a magnetic field, or a subsurface ocean. How can you classify a heavenly body you don't really know?

Caption by / Photo by Mark Wilson/Getty Images

If Charles Bolden, head of the American space agency, can still call Pluto a planet, so can you. “It's a big day for NASA,” Bolden said recently. “The U.S. today has become the first nation to visit every planet. We're calling Pluto a planet; technically it's a dwarf planet. I call it a planet, but I'm not the rule maker."

Not yet, anyway.

Caption by / Photo by Win McNamee/Getty Images
Published:
Up Next
15 creatures that could disappear w...
15