why is that all planets revolve the sun , maintaining the same distance to it. why not it move towards the sun, due to gravity. or move away from sun.
2006-10-02 18:16:57 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
Orbital tracks are not circular. Kepler discovered that planets move in orbital tracks that are elipses. That is, they are shaped more like "squashed" circles. As a planet gets closer to the sun, the move faster, which gives it the "boost" it needs to avoid hitting the sun. They then fly away from teh sun, slowing to a minimum velocity before falling towards the sun again.
Their tracks ARE affected by other planets - but not by much as the other planets' masses are so small compared to the sun.
In the web page I've sourced, there's an animator that shows you planetary motions. Left click to place your planet, and drag before un-clicking to give it a velocity!
2006-10-02 18:33:21 · answer #1 · answered by jbtascam 5 · 1⤊ 0⤋
This is due to the centrifugal force. When the sun exerts a gravitational pull towards the other planets those planets also exert a force opposing the force of the sun. The total amount of force thus produced by all the planets is almost equal to that of the gravitational pull of the sun. Though the forces are not exactly equal their difference, if considered, is extremely negligible compared to the average distance of the planets to the sun. Due to this reason the planets revolve in almost the same orbit. It is also because of the same reason that the electrons of an atom do not fall into the nucleus or move away from it,
2006-10-03 01:31:07 · answer #2 · answered by shubham.ghosh 1 · 0⤊ 1⤋
An orbit can be thought of as a continual fall offset by speed.
Gravity pulls the planet towards the sun, but the speed it's moving is trying to move it in a straight line from its current position tangent to the point it's at on the orbital curve. The planet is basically "falling" AROUND the sun. Those two forces balance to put a planet in its particular orbit.
Planets DO move in their orbits, by the way. Gravitational interactions with other planets or moons, asteroids or comets hitting planets, and other events can cause small changes in a planet's orbital speed, which can cause it to move closer to the sun or further away. Our moon, which orbits us, is actually moving further away from us by about 2 centimeters a year -- this is due to tidal forces it exchanges with earth, which slows its orbital velocity, moving it further from the earth. Things in space are almost always dynamic, but distances are huge and masses are great, meaning small changes take a long time to show much of a difference!
2006-10-03 01:23:51 · answer #3 · answered by Anonymous · 2⤊ 0⤋
In simpler terms, the planets were formed from debris being "pulled along" by the magnetic and gravitational forces of a central revolving mass (the sun)along the plane of its "equator". Eventually, all that "debris" (the planets) will "fall" into the sun. The orbits of the planets are not perfectly circular, they are elongated and get closer to the sun and each other at times, and pull away from same at other times. That is why every few years we hear of the earth being closer to Mars than it has been for the last hundred years, etc.
2006-10-03 01:52:11 · answer #4 · answered by Anonymous · 0⤊ 1⤋
It's all due to "conservation of energy" and "conservation of angular momentum". The other planets have really nothing to do with it. The stable elliptical orbit is the one in which (1) the sum of the kinetic and potential energy remains constant, and (2) the orbital angular momentum remains constant.
The planet's speed in orbit gives it its "kinetic energy". Its distance from the Sun is "potential energy". As it orbits, the planet exchanges kinetic energy for potential energy as it moves out to its furthest distance from the Sun ("aphelion"), then exchanges it back again as it moves closest to the Sun ("perihelion"). Energetically, there is nothing to prevent it from turning a sudden right angle and diving straight into the Sun. It would arrive there with a maximum of kinetic energy, and no potential energy at all.
However, heading straight for the Sun would leave the planet with no orbital angular momentum at all. The conservation of angular momentum means that this cannot happen (or, strictly, could only happen if the planet somehow gave all its orbital angular momentum to some other body).
2006-10-03 08:10:22 · answer #5 · answered by bh8153 7 · 0⤊ 0⤋
because of equal pulls of gravity from other planets ...if that was not the case there would be no planets orbiting the sun they would have crashed into the sun a long time ago..
2006-10-03 01:18:55 · answer #6 · answered by Marvin C 4 · 0⤊ 1⤋
planets are not only pulled by the sun but also by the planets. hence there is equal pulling between the sun and planets. this is why they don't move away from their orbits
2006-10-03 01:31:08 · answer #7 · answered by Anonymous · 0⤊ 1⤋
Due to gravitational pull.
Sun is like father to the babies planets.
2006-10-03 01:41:44 · answer #8 · answered by Mani G.India 4 · 0⤊ 0⤋
Gravitational force
2006-10-03 02:55:27 · answer #9 · answered by Mousey 2 · 0⤊ 0⤋
This is one moment you can realise the power of God. Scientists do not have an answer for this and they will try to avoid God for the fear of criticism.
2006-10-03 01:28:11 · answer #10 · answered by liketoaskq 5 · 0⤊ 1⤋