Thread: Extra Solar worlds

We have been discovering planets outside our Solar System at an impressive rate. Most are Jupiter size or larger. I was wondering how diverse planitary systems could be about other stars.

Is it likely that all planetary orbits are in a plane that is prety much perpendiculsr to the rotational axis of the parent star, as are those or our Solar System (Pluto is a slight exception)? Would orbits at drasticly different angles be stable? How about two ro more planets on the same orbit? ... or three Earthlike planets at close LaGrange points?

Such arrangements, if gravitationally possible would make for close Earthlike planets in a star system and short space-hops for a civilization evolving on any one of such planets.

yea buh as u were assuming while uploading this thread,i will also assume.planets at drastical angles from the sun?yea dey could be stable.gravity never mention position but their orbit will differ from the once we know and if so,occurlike the mecury anomalous movement will be observed.for planets like earth to be in one orbit? i strongly doubt since the curvarture of space will be more due to their closure.which will lead to different view of the universe from the planets.cosmologically think the planet will some the collide....and there are many .ore things to come which u won't like to assume.

yea buh as u were assuming while uploading this thread,i will also assume.planets at drastical angles from the sun?yea dey could be stable.gravity never mention position but their orbit will differ from the once we know and if so,occurence like the mecury anomalous movement will be observed.for planets like earth to be in one orbit? i strongly doubt since the curvarture of space will be more due to their closure.which will lead to different view of the universe from the planets.cosmologically i think the planet will someday collide....and there are many .ore things to come which u won't like to assume.

So are you saying that you believe any variation from all orbits in a plane and one planet per orbit woud be unstable?

How about three planets LaGranged in a single orbit? We know of a system of two bodys of close to the same size: Earth-Moon system.

as i pointed earlier,unstability am not sure of.but will assume it been stable since gravity did not mention position.and am not sure if earth and moon lie on same orbit.eath orbits the sun,and the moon orbit the earth...satellites orbit the earth.even human can orbit the earth jux if u can place urslf in an orbit.does that mean same orbit with earth round sun?

Well, Earth and Moon revolve about their common center of gravity and it is that center of gravity on the orbit that revolve about the Sun. There is also a center of gravity for the three oblects in a LaGrange system.

Originally Posted by Gary Wolf

Is it likely that all planetary orbits are in a plane that is pretty much perpendicular to the rotational axis of the parent star,

Yes, this is the most probable as typical due to how the system forms from dust and gas. The accretion disk will flatten out that over time will coalesce into stars, planets, etc.

Originally Posted by Gary Wolf

Would orbits at drastically different angles be stable?

An orbit at drastically different angles can be stable, yes. There's no rule that the orbit must be aligned with the plane, however, they are less common. This is because orbits with odd angles tend to be captured objects or objects that were moved from their original orbit (Perhaps by a close encounter with a large mass).

Originally Posted by Gary Wolf

How about two or more planets on the same orbit? ... or three Earthlike planets at close LaGrange points?

Again, it's technically possible but think of the odds of getting that to happen.

the odds are against that happening.and if they do,surely we can't know they do by observing other solar worlds from ours.its bullshit then.or you want to put some meaning into it.

Originally Posted by merumario

the odds are against that happening.and if they do,surely we can't know they do by observing other solar worlds from ours.its bullshit then.or you want to put some meaning into it.

I may have misunderstood you, here. What better way to try to know than to observe other worlds?

no better way fly...buh when the odds are against it,we should base on how this will affect the planets there.in doing so we could be point this possibility by its effect on planets...xo fly lets base more on the possible effects on planets in this kind of solar world.

A person can use simulators to model such motions. Such as this one: Planetary Orbit Simulator - Planetary Orbits - NAAP
This one is a bit more user friendly:My Solar System - Motion, Acceleration, Velocity - PhET

This last one is a simple one that I'm embarrassed to admit, has occupied hours of my time smashing planets together...:Planet simulation game | Planet Simulation - Free game site DAN-BALL

you really ain't serious.

Originally Posted by merumario

you really ain't serious.

Not always, no. But sometimes I am. Sometimes I've very serious.
When I said if a person is curious about whether certain planetary orbits are possible, they could use a simulator, was I serious?
Of course.
Was I serious with all the the links?
Not all of them. Sometimes it's more fun to get distracted and blow planets up.

Any questions?

nah i dnt think theres a question fly.goodluck while destroying planets. hope you can regonize earth.

Perhaps I am "dancing around" the actual question: "Could a stable star system exist with several Earth-like planets within say 10 or 20 million miles of one another?

Originally Posted by Gary Wolf

Perhaps I am "dancing around" the actual question: "Could a stable star system exist with several Earth-like planets within say 10 or 20 million miles of one another?

I'm not following this question because you ask "Within 10-20 million miles from eachother." Do you mean a constant distance?
At its closest, Venus (Which is roughly the size of Earth) is about 23 million miles away.

Are you asking about several Earth-like worlds in orbit around a parent star or several Earth-like worlds occupying the same orbit and balanced against eachother around the parent star?

Makes one wish these posts had a doodle application... Could draw a diagram.

Yes indeed, a diagram would be helpful. Yet, if a couple of "Goldilocks" worlds were only slightly more than a Moon distance away, planet hopping would be practical with our level of technology. Intersteller travel always leads to relatavistic paradoxes.

I was a fan of the all too short series "Firefly" (only about 12 episodes). I was hoping they would get around to explaining the planetology and relative distances in their multi- planet world. Looks like their ships had artificial gravity as well.

Originally Posted by Gary Wolf

Yes indeed, a diagram would be helpful. Yet, if a couple of "Goldilocks" worlds were only slightly more than a Moon distance away, planet hopping would be practical with our level of technology. Intersteller travel always leads to relatavistic paradoxes.

Well, the Moon is about 160,000 miles, significantly less than 20,000,000 miles...

Originally Posted by Gary Wolf

I was a fan of the all too short series "Firefly" (only about 12 episodes). I was hoping they would get around to explaining the planetology and relative distances in their multi- planet world. Looks like their ships had artificial gravity as well.

From what I understand, Wheedon wanted to avoid that as much as possible. He also was prone to refer to many of the worlds in the series as Moons.
The movie Serenity touched on it slightly at the very beginning of the film.

Owing to the moon's distance from earth yea it can...but having up to three of earth like planet at about that distance will make d planets spin slowly,due to d strong gravitational force...inverse quare law...venus is 42millionkm from earth.