What are the planets?

Question

The answer has gotten confusing now. Back when I was in third grade I learned it as Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.

Several years later, we were taught that there was a new planet called "Vedna" or something like that.

I've been tuned out of the whole planet thing, but know Pluto is no longer a planet. I look online and it lists the planets as they were back in the day with the original 9. Is Vedna (sp?) a planet or did they demote it to a planetoid? And can anyone confirm that Pluto is definitely not a planet?

I want educated answers please.

YEA - Sedna... sorry it's something I heard from middle school or soemthing.

And for those who found it unclear, my question is: "What are the planets."

Could anyone just list them out?

Thanks Linda :)

I think U covered it.

Answer 1

In August 2006, Pluto was demoted to "dwarf planet" status because it no longer fit the new definition of planet:
1. Had to be spherical due to gravity
2. Had to orbit the sun (and not another planet)
3. Had to have cleared its orbital path of debris.
Pluto met numbers 1 and 2, but since Pluto's orbit takes it into the Kuiper Belt (which is full of small objects), it didn't meet the 3rd criteria.

So the planets in our solar system (right now) are:
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Along with Pluto, Ceres (the largest asteroid) and Eris (another Kuiper Belt object) are the current dwarf planets in our solar system.

Sedna was an object discovered beyond the orbit of Neptune in 2003. It will qualify as a dwarf planet if it proves to be in hydrostatic equilibrium (meaning it is spherical due to gravity). But because its orbit takes it into the Kuiper Belt (like Pluto), it hasn't cleared its orbit of debris and so won't qualify as a full planet.
Besides Sedna, there are also between 16 and 40 other objects (most beyond Neptune, but some are in the asteroid belt) that are being considered for "dwarf planet" status.

Answer 2

Sedna not vedna is a minor planet found in solar system out side orbit of neptune. Quaor,iris etc were also found in the same area. They are all minor planets.But iris is massive and bigger than Pluto.Chances of finding more minor planets are very high. So They made Pluto a minor planet according to the new definition of a planet. As per International astronomical union,there are only 8 planets now. Pluto is a Minor or dwarf planet.
chandramohan.P.R

Answer 3

Ever since the decision of the International Astronomical Union in 2006, Pluto is no longer a "planet". It is, however, a "dwarf planet". All the other balls of ice that are discovered pass Neptune's orbit and have the same size (roughly) as Pluto are also dwarf planets (in addition to being Trans-Neptunian Objects (TNO) )

Because the definition of planet still has a few problems, there may be another redefinition in a few years. But by then, astronomers will have accepted the fact that Pluto is only one of a whole new class of objects that are not quite planets but are still big enough to be spherical.

--

The name you are trying to remember is Sedna.

Answer 4

people.......

Pluto is called a dwarf planet BECAUSE OF ITS ORBIT...... not its size, shape, distance or temperature.

it appears to "cut into" Neptune's orbit.

they say "it has not cleared the neighborhood"
1 of the three details the definition of "a dwarf planet"

* is it in orbit around the Sun,
* does it have sufficient mass so that it assumes a hydrostatic equilibrium (nearly round) shape, and
* has it "cleared the neighborhood" around its orbit.

http://physics.uoregon.edu/~jimbrau/BrauImNew/Chap13/FG13_20.jpg

people are upset by the new definition because technically NEPTUNE should be considered a dwarf planet as well.

http://www.sydneyobservatory.com.au/blog/wp-content/uploads/2006/09/imgp1444a.jpg
watch them vote..... see all the empty seats?

people are also upset because only about 300 of the people in the organization (7000+ total) where there to vote.

expect them to ALL come back and COMPLAIN in 2009 when the group meets again and they request a RE voting

and actually some astronomers REFUSE to call pluto a dwarf planet.

Answer 5

It's actually called Sedna and it has never really been declared a planet while Pluto has been demoted to a planetoid.

Answer 6

Pluto I learned is not classified as a planet but an object in space. It is I think still no considered Sedna is a planet or not some people classify it as a planet but other people classify it as an space object.

Answer 7

lol I have never heard of Vedna.. or whatever
BUT the Pluto thing I do know it was demoted to be a dwarf planet still a planet but not big enought to be considered an actual planet. lol

sorry if I confused you more haha...

Answer 8

Actually thats Sedna.More bigger than Pluto and also there is Eris.All of them are considered as a Dwarf Planet.

Answer 9

pluto is now officially a dwarf planet not a standard planet.
the name for the other planet you are thinking of is Sedna.

Answer 10

what is your question????????