The Cosmic Wheels — Why is Pluto now classified as not a planet?

1.5M ratings
277k ratings

See, that’s what the app is perfect for.

Sounds perfect Wahhhh, I don’t wanna
corruptedspacecore

Anonymous asked:

Why is Pluto now classified as not a planet?

astronomicalwonders answered:

So when Pluto was discovered in he 1840s we didn’t know nearly as much as we do now about our solar system. For example, we didn’t know that there was another belt of objects (similar to the asteroid belt) outside of the orbit of Neptune. Here it is:

image

We now know that this belt exists and we call it it Kuiper Belt. You see, this is when the problem began. We started discovering hundreds of icy bodies that were the same size as or larger than Pluto. (gif of Pluto):

image

What were we to do? should we now have a solar system with hundreds of Planets? It no longer made sense to call Pluto a planet when we found objects that were just like it (and in some cases larger than it) and did not classify them as Planets. Pluto clearly did not fit in with the planets, it fit in better with the icy bodies we had discovered.

Pluto is now classified as a Dwarf Planet, and I’m sure it is much happier there. It is no longer the smallest Planet, it is now one of the biggest Dwarf Planets.

Here is a good illustration of some of the larger objects that have been found in the Kuiper Belt sense it’s discovery:image

Thanks for the ask!

sagansense

Not-so-small correction: Pluto was actually discovered in 1930 by Clyde Tombaugh at the Lowell Observatory in Flagstaff, Arizona. Neptune, however, was discovered in 1846.

For further information regarding Pluto’s declassification, I recommend reading Neil deGrasse Tyson’s 'The Pluto Files: The Rise and Fall of America's Favorite Planet'. In it, you’ll find these wonderful gems below:

image
image
image
image

PBS NOVA also produced a 52-minute accompanying feature of the same name narrated/hosted by Neil deGrasse Tyson himself, which you can WATCH HERE. It’s basically a compressed version of the book, so if you don’t feel like reading, it’s a great overview.

image

Recently, Neil deGrasse Tyson was a guest on Late Night with Seth Meyers, whereby Neil discussed, COSMOS, science literacy, science fiction, comic books, his space-friendly vest, his presidential selfie with Bill Nye and Barack Obama.

The moment that made astronomy and TV history however, was his reconciliation with the now dwarf planet - Pluto.

image
image

When Pluto - ironically, an audience member in attendance that evening - confronted Neil about his “dwarf status” (in front of his human lady friend, no less), Tyson explained that the elements and atoms our home star is comprised of, are consistent with all of the precious bodies - large and small - amidst our solar system, including Pluto. This is not to be missed.