Questions for astronomers, and other assorted learned types

[Berzerker]

There is a theory that the (proto) Earth formed at the asteroid belt and got crunched maybe 4 bya - during, or starting the late heavy bombardment that preceded plate tectonics and life on Earth. Maybe time has destroyed or distorted evidence of this collision but it seems to me there might be patterns in the distribution of asteroids showing a "trail" back to the approximate location where "Heaven and Earth" were separated.

1) as I look at data on asteroids, all I get are orbital inclinations based on the ecliptic - where do I find this data based on the sun's equatorial plane and do the asteroids show any concentrations along it? Okay, thats two.

I'd like to see if there is a "tilt" or something unusual about the "plane" formed by the main body of asteroids. If its a trail of debris we might find the crumbs.

It seems to me the planets and asteroids should be orbiting the nebular plane, like Mercury around the Sun (or does it?). If they dont, why?

2) Does Saturn's rings "point" to Pluto when the latter is near or at perihelion?
3) Is there any significance in the similar ascending nodes of both objects?
4) Is there any significance in the 2:1 ratio in Pluto's closest and furthest distances after subtracting Saturn's distance from both?

According to the theory, Pluto was a satellite of Saturn and left it during some ancient disruption. I'm sure I can come up with a few more

[Egbert]

Berzerker,
I have no idea what the answers to any of your questions might be but the following link may be very helpful. The link will take you straight to the "Ask an Astronomer" page from the Cornell University website.

http://curious.astro.cornell.edu/aboutus.php

I had an astronomy question a few years and asked Cornell and received a very good and helpful reply.
Good luck.

[MikeH]

I think it's widely considered that the earth was created from accretion within the solar nebula, and hasn't shifted significantly from it's original orbit. If there is a theory that says it was created in the region that now houses the asteroid belt, and was smashed closer to the sun, and you can't find much evidence to back it up, I think that might give you your answer as to how likely it is.

The confusion may come because people regularly describe the solar nebula by saying it may have resembled the asteroid belt. But there's no trail because it didn't move like that. Solar Nebula and the planets and asteroids basically orbit in the same plane as the Sun's equatorial plane. It's basically the same data. Where planets drift from this plane it's either due to collision or influences of the gravity of other objects. The original nebula was disk like, but it wasn't 2 dimensional. And like current planets, objects didn't move in a 2 dimensional way. So there were collisions, and things got knocked out of the disk and attracted back in and through...

Wikipedia is pretty good on the basics of how the Earth and Solar System formed.

http://en.wikipedia.org/wiki/History_of_the_Earth

The planets other than Pluto (which isn't really a planet) do basically orbit in the nebular plane.

2. Kuiper belt objects like Pluto are massively influenced by Neptune, which is the most important factor for their orbits. Many of them (like Pluto) have a 3:2 orbital resonance with Neptune. Saturns rings are probably disintegrated objects that orbited saturn, with ring orbits based on the orbit of the original object, these may or may not have come from the asteroid belt.

http://en.wikipedia.org/wiki/Pluto

3. See 2.

4. Don't think so.

I think there's a theory that Pluto might have been a satellite of Neptune, which is much more likely. Never heard that it has anything to do with Saturn. Is that maybe the error that sprung all this confusion?

[Berzerker]

I think it's widely considered that the earth was created from accretion within the solar nebula, and hasn't shifted significantly from it's original orbit.

So where's the evidence of this massive collision suffered by the proto-Earth? Thats what I dont get... If the Earth was here when it got hit by a Mars sized object, we should see debris everywhere...like the asteroid belt. Thats where we see the debris, and the water. The asteroids occupy a zone where volatiles would have been blown by the solar wind and condensed, ie a planet rich in water.

If there is a theory that says it was created in the region that now houses the asteroid belt, and was smashed closer to the sun, and you can't find much evidence to back it up, I think that might give you your answer as to how likely it is.

Actually the evidence is everywhere, the more I look the more I see. I just dont see evidence of any collision in our vicinity.

but thx for responding y'all

[Egbert]

Saturns rings are probably disintegrated objects that orbited saturn, with ring orbits based on the orbit of the original object, these may or may not have come from the asteroid belt.

Interesting article on Saturns' rings in Wikipedia. Theory on how they formed, what there made of and how they are maintained. (I don't know much about astronomy so half of it went in one ear and out the other).

http://en.wikipedia.org/wiki/Rings_of_Saturn#F_Ring

I recall reading something somewhere about how geothermal activity on one of the moons shoots out vapour thus feeding a ring. Can't remember which moon (I think it was Pandora but not sure).

[Berzerker]

Does the Sun's equatorial plane changes over time? The Earth actually has a 7+ degree inclination to it, and I'd think the planets would be closer than 5-7 degrees. Kinda strange, aint it? The closer planets are about half the Earth's.

[KrazyHorse]

Does the Sun's equatorial plane changes over time?

At a guess, the only thing which could materially affect this is asymmetric solar radiation. The nutation of the Earth, for example, is relatively small, and its tidal counterparties (the Sun and the Moon) are much bigger, relatively speaking, than the Sun's

I'm not sure if there's any evidence for the plane of solar rotation over time. It doesn't seem like something that would have detectable effects over geologic time.

As far as the 7 degree tilt, I don't see what's that surprising about it. It's relatively small, and the formation of the sun and planets was a violent event.

[Berzerker]

thx Chief...maybe the comparison is invalid but the rings and main moons of Jupiter and Saturn are like mini solar systems and they orbit the parent's equator much closer.

is there any observational proof yet for the Oort Cloud? Or is it impossible for our instruments to notice such distant occultations from comets?

[Egbert]

is there any observational proof yet for the Oort Cloud? Or is it impossible for our instruments to notice such distant occultations from comets?

Apparently not.
See below for a cut and paste from Jet Propulsion Laboratories.

http://stardust.jpl.nasa.gov/classroom/activities/7-stardst-ch06.pdf

What is the Oort Cloud?
In 1950, Jan Oort noted that no comet has
been observed with an orbit that indicates
it came from interstellar space, there is a
strong tendency for aphelia of longperiod
comet orbits to lie at a distance of
about 50,000 AU, and there is no
preferential direction from which comets
come. He proposed that comets reside in
a vast cloud at the outer reaches of the
Solar System. This became known as the
Oort Cloud and is a spherical cloud of ice.
Long-period comets, those having orbital
periods greater than 200 years, were once
thought to have fallen into the inner Solar
System where the Sun would heat the ice
and it would transform into a comet.
Statistics imply that the Oort Cloud
may contain as many as one trillion
comets and may account for a significant
fraction of the mass of the Solar System.
Unfortunately, since the individual
comets are so small and at such large
distances, we have no direct evidence
about the Oort Cloud.

[KrazyHorse]

thx Chief...maybe the comparison is invalid but the rings and main moons of Jupiter and Saturn are like mini solar systems and they orbit the parent's equator much closer.

is there any observational proof yet for the Oort Cloud? Or is it impossible for our instruments to notice such distant occultations from comets?

There are some observations of candidate members, but no real "proof" of its existence yet. Note that my fields of expertise are only tangentially related to astronomy in general.