Bit small, and its orbit is a bit off (science word for that is “eccentric”). But there are no definite rules either way – it’s a matter of opinion – something that is “subjective”. There are some things that are Pluto sized that are not planets, and people were saying “Well, if Pluto is a planet what about these other things”.
It’s not terribly important, to be honest. The big planets are the cool ones, and so are some of the moons around the big ones, which people think might be possible places for life. Not people/elephants/flamingoes, but basic life. We shall see. Life on pluto? No. Ball of rocky freeze.
That wasn’t the answer you were looking for was it? You meant the other Pluto.
Pluto has always been a little bit different. First of all, it’s small, in fact very small. It’s smaller than the moon. Its orbit around the sun is different too. It is at a different angle to the rest of the planets moving around the Sun and it crosses Neptune’s orbit making it at times closer to the Sun than Neptune. See here for a picture. http://www.nasm.si.edu/etp/pluto/pluto_orbit.html
This led to all sorts of arguments amongst astronomers. Science definitions need to be exact and there were other things in the solar system that were around the size of Pluto that weren’t classified as planets. These went back and forth for years until 2006 when a vote was taken amongst astronomers at a meeting. Pluto was classed as a dwarf planet along with Ceres, Pluto, Haumea, Makemake, and Eris.
If we think of dwarf planets as a type of planet, (astronomers may just disagree with this but I have a soft spot for Pluto and really want it to still be a planet), our solar system has 13 planets of which five are dwarf planets. Whether Pluto is or isn’t a planet doesn’t change anything for us. Pluto is still there. What will change is the reports made by astronomers, instead of writing “the planet Pluto”, astronomy reports will have, “the dwarf planet Pluto”.
And anyway aren’t small things supposed to be cute looking?
When astronomers first looked at objects in the sky, they saw that certain lights moved relative to the fixed stars and they called them planets. That is how Pluto was discovered. A planet was any light in the night sky (“star”) that moved. Then they found more and more moving lights in the night sky that also moved. Some were big and some were small. They decided that the small ones were not planets. So they had to decide the question how big does an object have to be to be called a major planet. Then they found some objects that did not really look like a planet but were about the same size as Pluto — one was actually bigger than Pluto. So they decided that size wasn’t what defined something as a planet, and called these objects dwarf planets. Pluto was more like these other dwarf planets, so the CLASSIFICATION was changed.
Shakespeare wrote that a rose by any other name would smell as sweet. The name is not important, only the characteristics. Pluto is still Pluto: it hasn’t changed. What has changed is how scientists think of planets and how objects in the solar system are listed or classified.
Pluto has always been a bit of an odd one, out there at the edge of our solar system. It’s small and has an eccentric orbit, which means that it looks like a squashed circle, and it’s on a different angle to the other planets (there’s a good picture here: http://www.universetoday.com/13865/orbit-of-pluto/). This made classifying Pluto as a planet a bit awkward, but it got that name because it was the ninth biggest object orbiting the Sun.
When astronomers discovered other, larger objects outside the orbit of Neptune they had to decide whether to call these new objects planets or to change the classification of Pluto. So in 2006 Pluto became a dwarf planet. There are a couple of other objects which have been called dwarf planets, and many more which may be classified as such.
The new rules for classifying an object as a planet are:
1) Orbits the Sun
2) Is large enough to have become round due to the forces of its own gravity
3) Dominates its neighborhood by clearing other objects out of its orbit (this is where Pluto failed)
What? I always grew up learning that pluto was a planet. When did they change this and why was I not informed?!
🙂 Pluto was classified as a planet until not long ago, 2006 actually. Mat’s right. Like many types of classification, it’s a matter of opinion as to where the cut off is for a minor planet to graduate to a major planet. The short of the matter is that astronomers started to find other minor planets in the solar system that were bigger than Pluto, so Pluto had to be kicked out! Harsh, but fair probably 🙂
Bit small, and its orbit is a bit off (science word for that is “eccentric”). But there are no definite rules either way – it’s a matter of opinion – something that is “subjective”. There are some things that are Pluto sized that are not planets, and people were saying “Well, if Pluto is a planet what about these other things”.
It’s not terribly important, to be honest. The big planets are the cool ones, and so are some of the moons around the big ones, which people think might be possible places for life. Not people/elephants/flamingoes, but basic life. We shall see. Life on pluto? No. Ball of rocky freeze.
0
Pluto is Mickey Mouse’s dog.
That wasn’t the answer you were looking for was it? You meant the other Pluto.
Pluto has always been a little bit different. First of all, it’s small, in fact very small. It’s smaller than the moon. Its orbit around the sun is different too. It is at a different angle to the rest of the planets moving around the Sun and it crosses Neptune’s orbit making it at times closer to the Sun than Neptune. See here for a picture. http://www.nasm.si.edu/etp/pluto/pluto_orbit.html
This led to all sorts of arguments amongst astronomers. Science definitions need to be exact and there were other things in the solar system that were around the size of Pluto that weren’t classified as planets. These went back and forth for years until 2006 when a vote was taken amongst astronomers at a meeting. Pluto was classed as a dwarf planet along with Ceres, Pluto, Haumea, Makemake, and Eris.
If we think of dwarf planets as a type of planet, (astronomers may just disagree with this but I have a soft spot for Pluto and really want it to still be a planet), our solar system has 13 planets of which five are dwarf planets. Whether Pluto is or isn’t a planet doesn’t change anything for us. Pluto is still there. What will change is the reports made by astronomers, instead of writing “the planet Pluto”, astronomy reports will have, “the dwarf planet Pluto”.
And anyway aren’t small things supposed to be cute looking?
0
When astronomers first looked at objects in the sky, they saw that certain lights moved relative to the fixed stars and they called them planets. That is how Pluto was discovered. A planet was any light in the night sky (“star”) that moved. Then they found more and more moving lights in the night sky that also moved. Some were big and some were small. They decided that the small ones were not planets. So they had to decide the question how big does an object have to be to be called a major planet. Then they found some objects that did not really look like a planet but were about the same size as Pluto — one was actually bigger than Pluto. So they decided that size wasn’t what defined something as a planet, and called these objects dwarf planets. Pluto was more like these other dwarf planets, so the CLASSIFICATION was changed.
Shakespeare wrote that a rose by any other name would smell as sweet. The name is not important, only the characteristics. Pluto is still Pluto: it hasn’t changed. What has changed is how scientists think of planets and how objects in the solar system are listed or classified.
0
Q. What is a small thing with a beard?
A. A cold little dwarf called Pluto!
Pluto has always been a bit of an odd one, out there at the edge of our solar system. It’s small and has an eccentric orbit, which means that it looks like a squashed circle, and it’s on a different angle to the other planets (there’s a good picture here: http://www.universetoday.com/13865/orbit-of-pluto/). This made classifying Pluto as a planet a bit awkward, but it got that name because it was the ninth biggest object orbiting the Sun.
When astronomers discovered other, larger objects outside the orbit of Neptune they had to decide whether to call these new objects planets or to change the classification of Pluto. So in 2006 Pluto became a dwarf planet. There are a couple of other objects which have been called dwarf planets, and many more which may be classified as such.
The new rules for classifying an object as a planet are:
1) Orbits the Sun
2) Is large enough to have become round due to the forces of its own gravity
3) Dominates its neighborhood by clearing other objects out of its orbit (this is where Pluto failed)
0
What? I always grew up learning that pluto was a planet. When did they change this and why was I not informed?!
🙂 Pluto was classified as a planet until not long ago, 2006 actually. Mat’s right. Like many types of classification, it’s a matter of opinion as to where the cut off is for a minor planet to graduate to a major planet. The short of the matter is that astronomers started to find other minor planets in the solar system that were bigger than Pluto, so Pluto had to be kicked out! Harsh, but fair probably 🙂
0