What is the main difference between geocentric and heliocentric models of the solar system?
821367
One is incorrect and the other is correct.  The heliocentric model (or Copernican model) places the sun as the center of the solar system, with the planets revolving around it, which is correct.  \n\nThe geocentric model place the earth as the center of the solar system, with the planets and the sun rotating around it.  This is incorrect.  \n\nIn the 17th Century, the astronomer Galileo was branded a heretic and excommunicated from the Church for "daring" to challenge the Vatican's misguided belief (derived from a literal reading of the Bible) that the geocentric model was correct.  Science ultimately vindicated Galileo as correct, and the Church only issued a formal retraction of the excommunication of Galileo in this century.
134819
False  - the core is the core and the photosphere is a couple of zones beyond that.\n\nI couldn't get the other posted link to load, so I decided to answer so I could post a link for you, or others who are interested.
7432
If we just look at the sun, earth, moon system, all three bodies orbit the center of mass of this 3-body system.  Since the sun is much more massive than the other two bodies, the location of the center of mass of this system is inside the sun, so the sun moves very little, while the earth and moon appear to orbit the sun.\n\nNow, the earth and the moon also interact gravitationally, and they orbit the center of mass of the earth moon system  The center of mass of this earth-moon system is located inside the earth, so the moon looks like it orbits the earth.  \n\nYou can view the earth and moon as being in orbit around their center of mass, and the earth-moon system center of mass being in orbit around the earth-sun-moon system.\n\nIf the sun, earth, moon had equivalent masses, and if there were no other gravity bodies in the universe, they would appear to have orbits around the center of mass of this smaller earth, moon, sun system.\n\nI think the term"orbit" can be a little confusing because it's not always clearly defined.  The gravitational attraction of the sun on the moon is greater than the earth's attraction on the moon, so you could also argue that the moon really orbits the sun, with it's orbit modified by the earth.
1184119
Jupiter is further from the sun, and has a larger orbital path.  That is why it takes longer (it has to travel further to go around)
779719
Try NASA's site:\nhttp://www.nasa.gov/vision/universe/solarsystem/index.html\n\nor Wikipedia links from:\nhttp://en.wikipedia.org/wiki/Planets
11086
oops... misread.\nNicolaus Copernicus proposed the sun-centric model.\nhttp://en.wikipedia.org/wiki/Copernicus\n\nI think the geocentric model was assumed since the beginning of time.  Everybody saw the sun revolving around the earth.  It was obvious...
147445
Its all relative..usually we use sun as a point of a reference when we talk about relative size of planets which circle it. Pluto is about the same size as mercury.
217587
First I want to clear up that clockwise is really a 2-dimensional description of rotation, and planet rotation can be viewed in 3D so you can't really describe planet rotation as clockwise or counterclockwise. If you define an "up" and a "down" for the solar system, and then say "when viewed from above the solar system rotates counterclockwise", then the "anticlockwise" description works. For my answer we will assume you have done all this and that the solar system rotates counterclockwise, so there is no confusion from the wording of the question.\n\nThe reason the solar system rotates counterclockwise has to do with the way the gas clouds that created the solar system collided. They didn't collide head on. Think of cars travelling in opposite direction down an interstate hitting each other not quite head on (i.e. the left headlights of both cars smack together). When they do this they will spin out sideways - they will effectively rotate around each other (in North America with the cars driving on the right side of the road, they will rotate counterclockwise when viewed from above if they collide like this). The gas clouds did the same thing and their collision exceeded the critical density needed for gravity to take over and start forming the solar system, and as this matter collapsed to form the sun and planets, the rotation sped up. The rotation these gas clouds got from their collision gave momentum to the rotation of most matter in the solar system; the sun rotates in the same direction as those clouds did when they collided and so does most other things, including all the planets.\n\nSo that is why.
1166210
what is on the other side of the sun changes, as we and the other planets revolve around it, what "the other side" is, is a in a constant change...thats like asking what is on the other side of the world constantly as you are flying around it...  \n\nbeyond the Kuiper belt is what we call the Oort Cloud, where the Kuiper belt is in theory a significantly larger version of the asteroid belt, the Oort cloud is more spherical in nature completely encompassing the sun, solar system and Kuiper belt... beyond that deep space, other star systems, galaxies and the milky way...\n\n\nplease see the following diagrams...\n\nhttp://en.wikipedia.org/wiki/Image:Kuiper_oort.jpg\nhttp://en.wikipedia.org/wiki/Image:Oort_cloud_Sedna_orbit.jpg
779660
The Earth and Mars do not orbit the sun in perfect circles, they are ellipses.\nSo sometimes the Earth is closer to the sun than other times, and sometimes Mars is closer to the sun than other times.\nSo if the Earth is farther from the sun than normal at the same time Mars is closest to the sun, and this happens when both planets are on the same side of the sun, then we are closer to Mars than any other time and therefore we can see it better.
1179774
I could think of only two things that may (or may not) be that for which you are searching.\n\nThe first is simply a solar system mobile.  A simple string and crossbar mobile that children can put together.  Unfortunately a slight breeze could have them all going retrograde at once! Moons of the various planets are not generally included and the orbits are not elliptical.\n\nThe second is:\n"An orrery is a mechanical device that illustrates the relative positions and motions of the planets and moons in the solar system in heliocentric model. They are typically driven by a large clockwork mechanism with a globe representing the Sun at the center, and with a planet at the end of each of the arms." *\n\nI watched a program on Leonardo DaVinci and a section of this program had this tucked in the 3rd hour.  Coming back to find your question was interesting to say the least.   I hope this is what you need.
246461
No more than the earth does work orbiting the sun. An orbit has constant energy, and if it is not circular, there is a continuous process of exchanging kinetic energy with potential energy while the sum stays the same.
523675
Well geocentric theory by Ptolemy, as stated a while ago is the "earth-center" theory, this means that the earth is the center of the universe and all the celestial bodies revolved on it. The Heliocentric (by Nicolaus Copernicus), states that the sun is the center of the solar system, thus all the planets revolve on it. Both theories assume that the orbits of the planets, planetisimals, and other heavenly bodies are circular, but that is wrong. This was disproved by Johannes Kepler, accdg. to his famous Kepler's 1st Law, and all of his laws stating that planets revolve around the sun in varying eccentricities, (Venus has the almost perfect circle, and Pluto has the most ellipse orbit). He then favored Heliocentric theory.
1071275
Relatively speaking, If you look at the center of the galaxy as a major city, we are way out in the country, far away. \nThe Sun (and therefore the Earth and Solar System) may be found close to the inner rim of the Orion Arm, in the Local Fluff, at a distance of 7.94±0.42 kpc from the Galactic Center.\nIt takes the solar system about 225-250 million years to complete one orbit (a galactic year),[14] and so is thought to have completed about 20-25 orbits during its lifetime.
1127187
There are 3 debri clouds in our solar system.  The main asteroid belt lies between the orbits of Mars and Jupiter.  Another cloud, the Kuiper Belt, lies beyond the orbit of Neptune.  Far beyond that, the Oort Cloud lies at the very edge of intersellar space.  The closer two belts lie pretty close to the plane of the ecliptic.  The Oort Cloud is scattered 360 degrees around the Sun.
443497
They are one in the same. Both are based on the local time in Greenwich, England. This is the standard by which the scientific community bases their observations for things such as weather events or astronomical events, ect.
596684
The correct option is 'rotation of the earth'. When earth revolves, some part of it is directly facing the sun, and the other part is not. That explains the presence of day in one part of the world, and night in the other.