Science Pluto is demoted again

[Tinki3]

Poor Pluto has been demoted again. Calculations published on Thursday show the distant world that astronomers no longer deem a planet is not even the largest of our solar system's so-called dwarf planets -- it is smaller than recently discovered dwarf planet Eris.

Michael Brown and Emily Schaller of the California Institute of Technology used data collected from the Hubble Space Telescope and the Keck Observatory in Hawaii to determine for the first time that Eris had a greater mass than Pluto.

Eris, discovered in 2005 and named for an ancient Greek goddess of strife and discord, is 27 percent more massive than Pluto, they found. Eris is about half the size of Earth's moon, Brown said.

It was considered our solar system's ninth planet until August 2006, when the International Astronomical Union declared it a dwarf planet, a term referring to lesser, round solar system bodies orbiting the sun, mostly in an outer region called the Kuiper belt.

https://www.reuters.com/article/idUSN14471614/

 

[DM Cross]

Pft. What bull.

Pluto is the ninth planet in our solar system. Anyone who thinks wrong can ram it ^.^

 

[Uberplayer]

Thought that Pluto was 8.. well I had problems in geography, still having some

I hadn't even heard about this Eris ;D

 

[DuckieKing]

I had problems with Pluto being a planet only because its orbit was messed up. Obviously, modern science has kept up with my thinking, even if for the wrong reasons.

 

[phyrex1an]

Thought that Pluto was 8.. well I had problems in geography, still having some

Neptune and Pluto takes place being the 8th planet, or used to do until Pluto was demoted.

 

[Asehujiko]

Planets are supposed to fly in a circle arround the sun.
Pluto doesn't fly in a circle, doesn't stay in it's place and is smaller then some asteroids.

 

[phyrex1an]

Planets are supposed to fly in a circle arround the sun.

I wondered where the above statement come from until I read this I was pretty confused:

Pluto and Eris both follow elliptical rather than circular orbits as they journey around the Sun.

I seriously hope that the writer was fired, "all" planets follow elliptical orbits.

 

[Uberplayer]

How can we say which rock is planet..?

So are planets, the rocks or gas bubbles that circle around the sun?

 

[pheonixashes]

The IAU is stupid. Pluto first was at Planet, then Dwarf, and now what? Nothing. The culinary equivilent of Dishwasher.

A planet is determined by its pattern around a star, its power of its gravitational pull, and its rotation.


And phyrex1an, I think its the degree of ellipticality that determines if a heavenly body is qualified as a planet.

In other words...
Weak.

 

[DM Cross]

A planet is also determined by it's size, I believe. Which is really weak