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jaki
2004-Aug-28, 11:28 AM
I am sure this is a silly question but here goes nothing............ If a major asteroid were to hit Pluto and destroy it what would the effect on earth be? I would appreciate your comments on this. Cheers :-s

Tom Mazanec
2004-Aug-28, 01:25 PM
Gravitationally and tidally, miniscule (and I mean miniscule). There would likely be a LOT of shrapnel...say a million mountain sized pieces. A fraction of a percent will fall towards the inner solar system, and a fraction of those will eventually impact the Earth after some number of orbits. It will take at least decades, however, more likely centuries or millennia. But you would see continent crackers and asteroid winters eventually...maybe of Chixculub extent.

Joe87
2004-Aug-28, 01:59 PM
A planet won't "explode" due to the impact of an object as big as the largest asteroid or the largest known Kuiper belt object. Planets aren't bombs that only need a detonator to explode.[-(

Don't be fooled by the asteroid belt, it was not formed by an exploding planet - the total mass of the asteroids in the belt is much less than that of any of the existing planets. The asteroids are thought to have formed in place in their existing orbit. Their mass was too small to have agglomerated into a planet. Same with the Kuiper belt out beyond Pluto.

To affect anything as far away as the earth is from Pluto, the impacting object would have to be of a size comparable to the planet, for example, when the earth was hit by the planet/planetoid that resulted in the creation of the moon. Nothing we know of in the vicinity of Pluto is large enough to perturb the orbit of Pluto or to knock off enough large enough chunks of debris to potentially do any major damage to the earth if by some remote chance they hit the earth.

The newly discovered planet sedna beyond Pluto might be a problem if it ever hit Pluto, but it's a long way from Pluto, and it's orbit, as far as we now know, will never bring it near Pluto.

Now Planet X, if it's out there somewhere in interstellar space heading our way :roll: , might someday be a problem, but not in our lifetime. We know there's no Planet X in the vicinity of the solar system because if there were such a planet, astronomers would have seen it already.

If anyone (i.e., a *real* 'stronominer) has any corrections or additions to this, please add them.

Brady Yoon
2004-Aug-28, 05:34 PM
Don't be fooled by the asteroid belt, it was not formed by an exploding planet - the total mass of the asteroids in the belt is much less than that of any of the existing planets.

This isn't exactly the best argument. Most of the asteroids have collided with planets or left the solar system. In the past, there were a lot more asteroids. The best piece of evidence is that the larger asteroids have undergone differentiation, and that there are many different types. Correct me if I'm wrong. :wink:

jaki
2004-Sep-02, 02:21 PM
:D :D Ta for all of your help in my quest for knowledege regarding the Earth exploding, i seem to have a morbid curiosity about cataclismic events affecting our Green/Blue Jewel!! So now for my next question........Could anyone tell me if it is possible for the Earth to be "knocked" out of it's orbit and what the effect on us would be? I am grateful to you all for indulging me with these issues. Cheers....... :D :D :D

Argos
2004-Sep-02, 02:30 PM
Planets donīt explode like bombshells, like supermanīs planet Kripton. A huge impact could crack a planet all over, but the pieces would tend to be gravitationally bound, and they would eventually regroup. This is what seems to have happened to Miranda.

Edited for clarity

jaki
2004-Sep-02, 03:03 PM
The superman films was where i first got the idea of exploding planets from.It was a great scene though even if it could never happen like that in reality. I think that Miranda was formed in that way too.

Brady Yoon
2004-Sep-02, 04:38 PM
Ta for all of your help in my quest for knowledege regarding the Earth exploding, i seem to have a morbid curiosity about cataclismic events affecting our Green/Blue Jewel!! So now for my next question........Could anyone tell me if it is possible for the Earth to be "knocked" out of it's orbit and what the effect on us would be? I am grateful to you all for indulging me with these issues. Cheers.......

Hey, I'm like that too! :D Yes, it is possible but it would require energy on such a vast scale that all life would [probably] be exterminated in an instant, and the Earth itself might be destroyed. Not even the Mars-sized object that created the moon knocked the Earth out of orbit. If it did happen, the Earth would either spiral toward the Sun or leave the solar system; two bad alternatives.

JustAGuy
2004-Sep-02, 04:49 PM
If it did happen, the Earth would either spiral toward the Sun or leave the solar system; two bad alternatives.
Actually, no. Any impact would knock Earth from its current orbit to another, ever so slightly different orbit. Roughly, it might be slightly closer to the sun at perihelion (retrograde acceleration), or slightly further away at aphelion (prograde acceleration).

However, the other (aphelion for retrograde, perihelion for prograde) would remain the same. A single impact can only change one.

Spiraling in towards the sun would require constant retrograde acceleration--something an asteroid impact can't do.

And being knocked out of the solar system would require one massive bump in orbital velocity, something else that is highly unlikely.

Brady Yoon
2004-Sep-02, 04:55 PM
Actually, no. Any impact would knock Earth from its current orbit to another, ever so slightly different orbit. Roughly, it might be slightly closer to the sun at perihelion (retrograde acceleration), or slightly further away at aphelion (prograde acceleration).

However, the other (aphelion for retrograde, perihelion for prograde) would remain the same. A single impact can only change one.

Spiraling in towards the sun would require constant retrograde acceleration--something an asteroid impact can't do.

My bad. #-o

JustAGuy
2004-Sep-02, 05:01 PM
My bad. #-oAlthough we could lose all orbital velocity and drop straight into the sun, but this would require another Earth to smash into us at 30km/s opposite our direction (for a relative speed of 60km/s).

Somehow I don't think we'd be worried about dropping into the sun after that happened....