2007-05-28 12:39:44 · 16 answers · asked by drtimgarland 1 in Science & Mathematics ➔ Astronomy & Space
According to the new defintion, in 2007, there are 8 "planets".
There are also three dwarf planets (two of which were planets at one time) and a couple million minor planets (including the 3 dwarf planets which have retained their 'minor planet' designations).
There are 6 bodies that at some time in the past, were called planets but are no longer considered planets (nor dwarfs, nor minor): Sun, Moon, 4 largest satellites of Jupiter.
3 asteroids that were considered planets but are now minor planet: Pallas, Juno, Vesta
Summary:
Mercury: always was and still is a planet.
Venus: always was and still is a planet.
Earth: recognized as a planet in 17th century. Still a planet.
Mars: always was and still is a planet
Jupiter: always was and still is a planet
Saturn: always was and still is a planet
Uranus: discovered 1781 (1st reported as a comet); recognised as a planet later in 1781, still a planet.
Neptune: discovered 1846, immediately recognised as a planet, still a planet.
Pluto: discovered 1930 as a planet (thought to be bigger than Earth); reclassified as dwarf planet in 2006.
Io, Europa, Ganymede and Callisto, discovered 1610 by Galileo who reported them as "planets around Jupiter". Quickly reclassified as "moons" or satellites.
Ceres (1801), Pallas, Juno, Vesta were first classified as planets. For a while, everyone thought there were only 4 between Mars and Jupiter. With the discovered of Astraea and Hebe after a long gap, the first 4 were demoted to asteroid (and minor planet).
2007-05-28 13:02:16 · answer #1 · answered by Raymond 7 · 1⤊ 0⤋
Indeed, i agree with the above people, there is 8 that we know of.
Pluto used to be the 9th but it has in more recent times been discovered that Pluto is but a single example of a type of ice body which is very common in the outer reaches of the solar system and is therefor not a planet after all.
2007-05-28 12:50:50 · answer #2 · answered by LostSoul 2 · 1⤊ 0⤋
Currently there are 8. Pluto isn't a planet scientist's say. But I did find out that there is a planet that's a member of the kuiper belt. The planet's are Mercury,Venus.Earth,Mars,Jupiter,Saturn,Uranus ,Neptune
2007-05-28 13:31:32 · answer #3 · answered by Anonymous · 0⤊ 0⤋
hm mm...a travel question. let's see... which planet in our solar system revolves fastest around the sun? I believe that would be Vulcan. Fascinating. Given the Newtonian laws of physics governs the planet's motions, then Vulcan would be the correct answer. Live long and prosper. ps - assume each orbit is circular and divide the circumference by the # of days in a 'year' (for that planet) and those answers will give the fastest planet. probably mercury.
2016-05-20 01:29:32 · answer #4 · answered by ? 3 · 0⤊ 0⤋
there was 9 but they decided pluto was not a planet then they thought they(scientists) had found another planet so really i dont know either 8 or 9.
2007-05-28 12:47:33 · answer #5 · answered by Anonymous · 1⤊ 0⤋
8 planets currently.
2007-05-28 12:47:00 · answer #6 · answered by Dr. Eddie 6 · 1⤊ 0⤋
8, pluto is a minor planet
2007-05-28 12:45:45 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Eight. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
2007-05-28 12:45:09 · answer #8 · answered by Anonymous · 1⤊ 1⤋
I thought it was 8 regular (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune), and then the two dwarf - Pluto and the new one, Eris.
2007-05-28 14:08:16 · answer #9 · answered by xstaticadventure 2 · 0⤊ 0⤋
actually its 9 again. scientists classified pluto as a dwarf planet, but now they have reconsidered it as a regular planet that might have been a astroied.
2007-05-28 13:36:30 · answer #10 · answered by twisternycxx 4 · 0⤊ 0⤋