Jon

How many planets are in the Solar System?

Tuesday, 29. August 2006, 01:18:29

How many planets are in the Solar System? This popular question now has a new formal answer according the International Astronomical Union (IAU): eight. Last week, the IAU voted on a new definition for planet and Pluto did not make the cut. Rather, Pluto was re-classified as a dwarf planet and is considered as a prototype for a new category of trans-Neptunian objects. The eight planets now recognized by the IAU are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Solar System objects now classified as dwarf planets are: Ceres, Pluto, and the currently unnamed 2003 UB313. Planets, by the new IAU definition, must be in orbit around the sun, be nearly spherical, and must have cleared the neighborhood around their orbits. The demotion of Pluto to dwarf planet status is a source of continuing dissent and controversy in the astronomical community.

Credit: International Astronomical Union
http://antwrp.gsfc.nasa.gov/apod/astropix.html

For a Screen Wide version (1024 pixels wide): http://snipurl.com/vmw5-TE02NA

For the APOD version: http://antwrp.gsfc.nasa.gov/apod/image/0608/planets_iau.jpg

For the original large version: (6000 pixels wide) http://antwrp.gsfc.nasa.gov/apod/image/0608/planets_iau_big.jpg

Name This Astronomical Beauty!Don't be Afraid

Comments

Eliane a/k/a Elly # 29. August 2006, 03:25

this is a cool pic. Now I know where Ceres and the newest dwarf planet are.

Ivy # 29. August 2006, 11:48

eight?night?ten?
haha..i don't show much concern on it...
xixi...

but i know the third one--the planet of earth--where we live...
haha...

Jon # 29. August 2006, 12:11

Hi Ivy
Nice of you to visit.
See you!
Jon

Ivy # 30. August 2006, 06:57

hey.,,jon..
try this link...
haha..jon...
http://bbs.chinadaily.com.cn/index.php
i am ivyfantasy there....

next was my reply to you on your reply to my artical entitled "on solitude" and you will see what i want to tell you:
haha..jon...
this is a discussion in the forum of chinadaily....
you can sign up with a name and log in,participating in the discussion too....
this is the link:
http://bbs.chinadaily.com.cn/index.php

xixi....
remember la...

Jon # 31. August 2006, 04:28

:-( Somebody already uses the name chinajon there!
Don't confuse me with that guy!

;-D Have a good time learning English!

Kay Four # 2. September 2006, 14:57

Hello Jon,

I am old school. I still think of Pluto as a planet. But then maybe DWARF Planet counts as a planet, too.

But I think 2003 UB need a REAL Name. I am voting for KayFour!

Jon # 3. September 2006, 05:27

I think so.
A dwarf is a person, right?
It's how much we love them that matters!

hahaha

Eliane a/k/a Elly # 5. September 2006, 05:13

What happened to troll?

I adore that Wall of China in fog picture you have here!!!!

Eliane a/k/a Elly # 9. September 2006, 05:58

Every time I visit you, you have a new photo!

Is that a jade marble?

It is so beautiful!!

Jon # 10. September 2006, 14:31

I made a fake planet. I call it Magella. Thanks for thinking it is beautiful!