Earth with Rings

Grumpy RPG Reviews

Explorer

• May 2, 2013

• #1

[video=youtube;UT2sQ7KIQ-E]http://www.youtube.com/watch?feature=player_embedded&v=UT2sQ7KIQ-E[/video]

 

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Umbran

Mod Squad

Staff member

Supporter

• May 2, 2013

• #2

I've considered once or twice seeing if I could work through the math of whether such a ring system would be stable in the Earth-Moon system.

 

darjr

I crit!

• May 2, 2013

• #3

I'd love to know if it's stable. I wonder how much tonnage of ice and other material it consist of.

 

Umbran

Mod Squad

Staff member

Supporter

• May 2, 2013

• #4

Well, Saturn's rings mass about 3x10^19 kg. That's small when compared to, say, our moon, which is pretty darned big. So, Saturn's rings, all told, are a small moon sized mass.

What rings around Earth would be is apt to be a different question altogether.

 

T

tomBitonti

Adventurer

• May 2, 2013

• #5

Minor gripe: Would it cast a shadow? Would it cast that dark of a shadow?

I thought the Saturn rings were unstable, but were being fed by outgassing from moons.

Thx!

TomB

Edit: Can anyone figure if the brightness levels are correct for the from-earth images? I have this suspicion that the brightness is way off, since the reference image is at a very low intensity. Putting those same rings around earth with our brighter sunlight might give a very different relative brightness of the rings against the earth or against the day or night sky, than we see of the Saturn rings against Saturn.

 

Last edited: May 2, 2013

sabrinathecat

Explorer

• May 2, 2013

• #6

An impressive piece of work.
Wouldn't the Moon's gravity have some distorting effect on the orientation or orbit of the rings? Sorry, my astrophysics is a little rusty, (OK, bordering on non-existent).
Fun idea for a gaming world.
Think what that would have done to Da'Vinci, Copernicus, and Newton, and their views and figures.
How would it have affected the legends and mythology?

 

Nellisir

Hero

• May 2, 2013

• #7

I think rings around the Earth are possible, even with the Moon - Jupiter, Saturn, Uranus, and Neptune all have rings and moons. A bigger issue might be the size of the Earth - the gas giants in our system all have rings, but none of the rocky planets do. That's suspicious.

 

O

Olgar Shiverstone

Legend

• May 3, 2013

• #8

We already have rings ... of space junk.

 

Umbran

Mod Squad

Staff member

Supporter

• May 3, 2013

• #9

tomBitonti said:

Minor gripe: Would it cast a shadow? Would it cast that dark of a shadow?

Click to expand...

Google image search "shadow of rings of Saturn". The sun isn't as bright that far out either, but the shadow can be substantial, if the ring is dense.

Edit: Can anyone figure if the brightness levels are correct for the from-earth images?

Click to expand...

In a word, no. The brightness would depend strongly on the composition and density of the rings.

sabrinathecat said:

Wouldn't the Moon's gravity have some distorting effect on the orientation or orbit of the rings?

Click to expand...

Distortion, or perturbation to the point of destabilization are both possible. That's why I said I had wanted to do the math to see if it were stable - the Moon could have much influence.

Nellisir said:

I think rings around the Earth are possible, even with the Moon - Jupiter, Saturn, Uranus, and Neptune all have rings and moons.

Click to expand...

Yes, but the masses of those moons are close to negligible as compared to the mass of the planets. Meanwhiile, our Moon is not negligible as compared to the mass of the Earth.

 

Nellisir

Hero

• May 3, 2013

• #10

Basically what I'm reading (from around) is that rings are possible and have happened, but not stable on a scale of billions of years - and this is true of all rings. The reason terrestrial planets generally don't have (stable) rings and gas planets do is a function of size and mass - the greater the size/mass, the larger the Roche limit, which is the point at which a planet rips apart a spherical body (making it into rings). We have a small Roche limit; gaseous planets have large ones.

The Moon would make a circular ring around the Earth impossible, but an elliptical (or braided?) one might be possible. Less stable, though. Hundreds of thousands of years, not billions

Earthrings would likely be made of dust/rock, not ice.

http://www.astroscience.org/abdul-ahad/earth-ring-dynamics.htm
http://timtyler.org/the_rings_of_earth/
http://van.physics.illinois.edu/qa/listing.php?id=16353
http://kosmo.hubpages.com/hub/Does-the-Earth-Have-Rings-Like-Saturn