how many planets in our solar system it seems to changing all the time nowadays?

Answer 1

10 ... Xena just discovered again with a moon is larger than Pluto.

A non luminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves. In the solar system there are nine known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.

Xena is larger than Pluto and it has a moon. It was first discovered about 3000 years ago. I am not going to throw away a planet for anyone.

Answer 2

the planets are mercury, venus, earth, mars, jupiter, saturn, uranus, and neptune. that is eight planets.

http://www.iau.org/fileadmin/content/pdfs/Resolution_GA26-5-6.pdf

this same thing has happened before. beginning in 1800, astronomers found a few bodies orbiting between the orbits of mars and jupiter, and they finally stopped classifying them planets after several discoveries. astronomers then added numerals to the names, and pluto recently got its numeral. 150 years from now, no one will think of "134340 pluto" as a planet. very few will even know we classified it as a planet. "1 ceres" and "136199 eris" are other dwarf planets. before the vote by the international astronomical union on 24 august, the iau seems to have been considering classifying "1 ceres", "136199 eris", and charon planets.

pluto is not a planet. pluto and charon are considered a binary system, but two small bodies orbit this system. they are called nix and hydra. this does not change anything about the solar system or pluto. it just corrects the mistake of classifying pluto as a planet initially.

http://en.wikipedia.org/wiki/Pluto

pluto orbits the sun, is round, does not have an isolated orbit (a bunch of other similar bodies have similar orbits.), and is not a satellite so it is a dwarf planet.

i have been waiting for this since i was about twelve. i feel somewhat satisfied. i knew that pluto didn't fit the pattern set by the major bodies in the solar system so it was an anomaly. it just felt illogical and "out of place". this was the right thing to do, believe me. i don't understand why so many are having such a problem with this.

i don't know how long this will drag on tho. many planetary scientists are not satisfied that the definition is rigorous enough.

Answer 3

The number of known bodies traveling around our sun will always increase as we obtain better technologies to make those discoveries. You have been hearing the arguments going around in scientific circles about how we are to define what a planet is. It seems that there are quite a few heavenly bodies going around the sun that are larger than Pluto yet no one wishes to call them planets while at the same time they argue about Pluto's status as a planet if the others are not. Just in the last two months the argument came to a head and the decision was made that Pluto is no longer a planet.

I'll bet if you were to get out your telescope and take a look at her now she probably still looks the same as before. Pluto doesn't care if she is a planet or not.

I hope this shed a little light on the subject.

Answer 4

Angela is so wrong. The number has changed several times in the last 500 years. Pluto is merely the most recent to be demoted in a long line of expulsions from the planetary club. We should be getting used to this by now!

Our story starts with the 8 objects known since antiquity: Mercury, Venus, Mars, Jupiter, Saturn, the Sun and the Moon, which were all thought of as planets, and the Earth which they were supposed to be going around, which was supposed to be the centre of the universe, and therefore NOT a planet.

So there were once 7 planets

The first two demotions, with the acceptance of Copernicus' theory of a heliocentric solar system, proposed in 1543, were the Sun and the Moon. So we were down to 5 planets.

And the earth got taken into the planetary club. And then there were 6 planets.

Wikipedia sums up what happened next as follows:

"Since the acceptance of the heliocentric model over the geocentric model, the solar system has been seen as having various numbers of accepted planets over the years, based on culture and scientific consensus:

1543 - six (Mercury, Venus, Earth, Mars, Jupiter and Saturn) (among those who accepted the new view)

1781 - seven (with Uranus)

1807 - eleven (with 1 Ceres, 2 Pallas, 3 Juno and 4 Vesta)

1845 - twelve (with 5 Astraea)

1846 - thirteen (with Neptune)

1851 - twenty-three (with 6 Hebe, 7 Iris, 8 Flora, 9 Metis, 10 Hygiea, 11 Parthenope, 12 Victoria, 13 Egeria, 14 Irene and 15 Eunomia)

1852 - eight (without Ceres and the asteroids)

1930 - nine (with Pluto)

2006 - eight (without Pluto)

When the objects 1 Ceres, 2 Pallas, 3 Juno and 4 Vesta were found orbiting between Mars and Jupiter in the early 1800s, they were declared and accepted as planets, and this remained the case for many years. However, as more and more objects began to be found in the same region of the solar system, they became classified as asteroids, along with their orbital kin.

(Just as well they did, really, as we now know of 340,000 asteroids and to have them all classed as planets would be getting rather silly.)

A similar scenario has occurred with Pluto. It was first discovered beyond Neptune in 1930 and was accepted by the IAU as a planet after it was initially believed to be larger than the Earth. However, after further observation it was found that Pluto was actually much smaller, being less massive than the Moon.

After more than 1,000 similar new bodies were found beyond Neptune during the 1990s and the early 2000s, the IAU decided to reclassify Pluto as a dwarf planet in 2006."

On another page, (see 2nd link) Wikipedia argues that besides these 18 demotions, there were another 9 as the first 7 moons to be discovered in the 17th Century were all called planets by their discovers at first, but the idea of a new category of object called "moons" came to be accepted, as more and more were discovered.

And further, both Sedna and Eris were widely hailed by the press as the tenth planet when Mike Brown and his team discovered them in 2003,

So that makes 27 sets of second thoughts about objects that were greeted as planets when first found, but came to be demoted later.

We now know of 162 moons around the 8 planets and 80 or more around asteroids and Trans Neptunian Objects (TNOs),

242+ moons
1000+ TNOs
340,000+ asteroids
3 dwarf planets and maybe another 40+ will be accepted as dwarf planets

The solar system, which was thought to have just 8 objects in it, less than 400 years ago, is filling up, rather rapidly and you can see why it is better to have several separate categories, rather than one all-embracing category called planets, and why reclassification and demotions were judged to be necessary,

Answer 5

Dude, the number has only changed once. Pluto is no longer considered a planet of our solar system because its orbit passes through a region that has been deemed outside our solar system since its discovery. There are 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Answer 6

brucebirchall gave a fantastic answer but i would like to add that pluto was demoted at a meeting where certain newly discovered bodies were considered for official naming of planets. As you now know numerous asteroids were downgraded from the status of planets to minor planets around the time of the renaissance. If these new bodies were to be classed as planets then it would have required that certain asteroids also be promoted back to being major planets. As Pluto isnt the largest of these dwarf planets it could hardly be left with full planetary status, especially since it has a highly eccentric orbit.

Answer 7

8 official planets, and two sub planets, Pluto and the other one lol.

Reason for this is that the 'other one' is bigger than pluto 1400mi diamenter, pluto 1200, and these sub planets sit in a large belts of stuff, prob ice/gas blocks, so they, the clever ones, think that with all the new technology that even more 'planets' of pluto's size will be found, making hard to keep up , so we have sub planets and planets, 8 planets and 2 sub planets,(is that 10planets ? ) watch the sub planets grow in number. personally I'd call them Orbs then the word planet would only be used for planets, it's like having half a hole lol

Answer 8

We have 8 major planets, 3 dwarf planets, and thousands of minor planets discovered and classified so far. There are three majors that have not been discovered yet, 20 dwarfs and several thousand more minors, all out near the Ort cloud of comets. I also have a bridge in New York for sale.

Answer 9

Currently eight: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto was considered a planet until August, when it was reclassified as a dwarf planet.

Answer 10

8 - Pluto is no longer classed as a planet