Why is there only one planet in each orbit around the sun?

Question

Please explain. I am very sorry to say it is a question for my science homework and this is sort of cheating, but i dont get how to explain it and my teacher won't like that answer.

Answer 1

Tell him The laws of physics only allow one valence electron per orbit.

Answer 2

Funny, I was thinking about this just yesterday. Imagine there were two Earths in the same orbit around our sun, with the other on the opposite side of the sun from us. (Call the other one "Counter-Earth.")
Over a long period of time, the two planets would have different experiences. Say, one would be where a solar flare hit; the other would get hit by a meteor. At different times, the other planets would pull on the two Earths differently.
Over a long long period of time, one of the Earths would be slowed down with respect to the other. Eventually, they'd collide.

Good thing planets don't form more than one to an orbit (see the other answerers for the reasons behind that).

Answer 3

There actually isn't a simple answer for that, but during formation of the solar system, where accretion occurs that ultimately form the planets, once a mass forms in an orbit about the sun, it tends to sweep all other other matter out of its own orbital band, either throwing them out of orbit, or pulling them in and adding to its own mass. Having two planets in the same or close orbits are unstable, they would either eventually collide (which is one of the hypothesis for the formation of the Earth's moon, after such an impact), or one or the other will be flung into a new orbital path.

Answer 4

That's just the way things happened after 4.5 billion years of existence. All the matter in the Sol Nebula clumped together to form the planets in their respectve orbits. There may have been more objects in the same orbits in the early years of the Solar System, but with different masses, they would have orbitted at different speeds and collided anyway to form one larger mass.

Answer 5

Hypothetically if two planet were put in the same orbit around the sun they would most likely crash and slowly combine into one large planet.

Answer 6

When the planetary nebula was forming, it differentiated into one planet per orbit. If there had been more than one, their speed would never have been exactly the same. Eventually they could collide.

Answer 7

because eventually at one point in time the two planets would collide sine the solar system is old it probably already happened. there might have at one time been two planets in one orbit but they would have already collided

Answer 8

if there were more then one planet/object on same orbit at some point they would collide

Answer 9

planets are so big they're sizes could not exist in the same orbit for gravitational reasons. aka they draw into one another till they crash.

Answer 10

Planets are formed by aggregation, so all the little bits within reach get hoovered up by gravity.