how do the planets hold to their orbits around the sun?
354530
Each planet is attracted to the Sun by the Sun's gravity.\n\nHowever each planet is traveling at a certain speed tangential to its orbit. \n\nThe sun's gravity curves (pulls in) the trajectory of the planet.\n\nThe faster the planet is moving, the further it can get away from the Sun.\n\nA kind of balance between the speed of the planet and the Sun's gravity at the location of the planet result in the final orbit of the planet.\n\nIf we were to speed up a planet, its orbit would move outwards.\n\nIf we were to slow down a planet, its orbit would move inwards (towards the Sun).\n\nCordially,\nJohn\nhttp://www.GodSci.org
32921
Um... what are you asking here?  I think an answer would be that the planets revolve around the sun because the sun it so massive that it makes a small 'dent' in space-time, and the planets 'fall' towards the depression.  There are 9 planets in the solar system, and Earth is the third from the sun and the largest of the inner rocky - planets.  Many of the planets have satellites, called moons.  Earth's moon is called Luna which is (relative to the size of its planet) particularly large.  The planets also rotate on their axises (which is why we have, among other things, night and day).  Nearly all planets also have an atmosphere, a layer of gas that exists above the planet's surface, though only Earth has an atmosphere suitable for breathing.   Beyond Pluto, the last official planet, is a very large void followed by a large collection of planetary fragements (meteors), then another large void.  The solar system ends at a boundry called the heliopause, the outtermost reaches of the sun's solar winds (think of it as a wind made of radiation).  If you travel through the heliopause, you would experience an arguably extreme 'termination shock' as you enter an even larger void into intersteller space.  Okay, that's all I got.
627517
The sun is the center of the solar system, revolving around it are the nine planets namely: mercury, venus, earth, mars, jupiter, saturn, uranus, neptune and pluto.
874175
They are falling down into the sun. It is their foward motion that prevents them from plunging into the sun and getting vaporized.\n\nIf you go out at night and look at a planet, you will see that it rises in the east and sets in the west, just like everything else in the day or night sky, as a result of the earth's rotation on its axis. From one night to the next, you will see the planets (usually) appear to travel eastward against the background of stars, as a result of their revolution about the sun.
93675
(1) They're all spherical in shape\n(2) All orbit around the Sun\n(3) All rotate on their axis
463132
Yes,it exerts gravitational pull and it is due to this gravitational pull all the planets are revolving around the sun in fixed orbits.
903588
The International Astronomical Union (IAU), the official scientific body for astronomical nomenclature, defines a "dwarf planet" as a celestial body that, within the Solar System,\n\n    (a) is in orbit around the Sun;\n    (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape;\n    (c) has not cleared the neighbourhood around its orbit; and\n    (d) is not a satellite\n\nIt differs from the definition of "planet" in that a dwarf planet has not cleared its orbital neighbourhood.
292052
That's a really good question, that doesn't have an answer yet.  The current theory of solar system formation suggests that planets spin in coordination with the orbital spin of the disk of matter that forms the core of the solar system.  The spin of the accretion disk itself is the result of conservation of angular momentum, and can either be clockwise or counter-clockwise, which would be a relatively random process.\n\nThere are 'accidents' however, whereby planets are impacted by other large bodies in random ways and can greatly skew the planetary orbit and/or spin.\n\nSometimes the results are really weird, such as Uranus, which rotates top-to-bottom relative to the plane of our solar system.\n\nFrankly, until we're able to do a survey of planets in our galaxy and a few others, I think it would be hard to guess what the real averages would look like, and whether or not they are random.
1048885
The body of planets, their moons and other objects that orbit the Sun.
671321
This is sort of true, but not entirely. Mercury has a very fast orbit around the sun, and a very slow rotation about its axis - in fact, the "days" are longer than the "years."  Additionally, Mercury's orbit is very erratic - sometimes it gets really close to the sun, and other times it gets further away.  During the times when its orbit is getting closer to the sun, the gravity acting on it makes it speed up.  When the planet speeds up then the relative speed of the planet's orbit and its rotation change.  The result is that the sun would appear to rise about halfway, go back down again, and then start rising and setting normally.  This happens only in the eight or so Earth days around "perihelion" - the time when Mercury is closest to the sun.
948233
They have solids cores.  Other than that the are mostly gas, due to the distance from the suns gravity.  When our solar system was formed most of the "heavier" elements stayed close to the major gravity pull, the sun. once out any other heavy elements that made it out that far condensed to gether to form cores.  Now; the farther away from the sun you go the coder it gets.  Now the gases that are out that far basically freeze and get "solid".  hope this helps!!\n\nBy the way- ALL planets need a core.  even though it might not be of same rocky material as other planets (Jupiter, saturn)..think of my explaination above.  If none of the solids came out that far out, they could get together to form a core, but something has to be in the center of a planet.
182160
First of, there's no force causing planets to rotate. \n\n"Most of the rotation comes from the conservation of angular momentum. The formula is L=m*w*r2 where m is the mass, w is the angular velocity in radians per second, and r is the radius of the circular motion. Due to conservation of angular momentum, if the radius of the orbit decreases, then its angular velocity must increase (as the mass is constant). \n\nAnyway, the bottom line is that stars like the Sun spin from the original angular momentum that was there in the solar nebula from which it formed. Not only that, all orbital motion of the planets (including the spin) is due to this orginal angular momentum."
1015345
The Earth rotates on its access and revolves around the Sun.
884425
well the path of the planets is different for each due to the size but the are similar to a oval type shape, gravity hold the planets in orbit and as far as the asteroids they are freely moving until caught by a gravitational pull of a larger object
108530
Not all the planets do rotate on their axes with constant angular velocity (see reference) and even two rotate in the opposite direction to earth (counter clockwise when viewed from the celestial north pole); venus and uranus (called retrograde motion). \n\nThe rough alignment of all the angular momentum vectors in the solar system, including orbital and rotational angular momenta of all the planets, moons and the sun is presumably a left over relic from the angular momentum when the system was formed from a rotating gaseous collection of material.
711289
Actually, those circles are NOT perfect.  They're slighly elliptical.  This is called the excentricity of the orbit.  \n\nBut, yeah, they are more or less on circles, and that's because they want to go straight forward (inertia) but the pull of the Sun's gravity stops them from goind away.\n\nIt like tieing a ball on a rope and turning it around.  It makes a circle.  Let go of the rope, and it will go on a straigt line.  The rope is the Sun's gravity.
374997
The sun is the larger object. So, it has more gravity. The earth moves around the sun and centrigfugal force keeps it going around rather than crashing into it. It continues to move because there is no gravity or atmosphere in space to slow it down. Once a spaceship or rocket leaves the earth's atmosphere and pull, it keeps going even without its rockets on. It just keeps going in the direction it was pointed. \n\nTo learn more, see http://spaceplace.nasa.gov/en/kids/phonedrmarc/2002_july.shtml