i have read (with great interest) all the posts of predictions and what ifs about if our Earth was to be hit with a rogue rock from space.

now what if it was to hit the moon ?

i know the moon is a fair distance from the earth etc and it would have to be a chance in a billion to actually hit the moon at an angle to knock the moon into the earths path but..

what size object would be needed to succesfully knock the moon out of orbit?

would you think a .5km asteroid colliosion with the moon could actually be worse for us than the same size rock hitting us directly - ie. zero gravity explosion in our direction , considering the amount of actual moon that would be uplifted to somewhere else ratio to the size of impact object.

thoughts please ?

If something hit the moon, the debris from the impact would come to Earth. I think the only thing that could make the moon itself come towards Earth would be another gravtational object near it.

If an asteroid hit the moon (And destroyed it or severly damaged it as say taking a massive chunk out of it) it would be worse for us imo

Due to the earth party been reliant on the mood with weather effects and the sea

Also the earth would lose its balance due to the moons gravitation effects (Along with the sun)

So yes imo it would be far worse due to not being able to recover fully without getting a new one

[Edited on 25-5-2004 by Crash]

I agree, I think an impact with the moon could produce a more devastating set of circumstances for earth primarily due to the tidal and weather impact.

That would make for one heck of a visual display either way. Remember the old Thundar the Barbarian cartoons? Wasnt that what happened to the moon at the beginning of the cartoon?

ok my reasoning for this question originally was -

it is claimed on a few sites that a .5km wide bit of rock would cause global darkness upon the earth and turn it into a nasty place to live , destroying most oxygen giving life etc.

now going by the the assumptions of scientists who say that a rock about 1 miles across would create about a 10+ mile crater ,now im assuming a .5 mile rock slamming into the moon would upheave roughly a 5mile bit of moon and due to the lack of gravity , would propell this chunk out into the space and possibly into the direction of us - ok it would lose a bit of speed etc but it would still be a large chunk of rock falling upon us.

ok its a longshot here as the moon is about 20 times the width of the earth away from us , but if a chunk was ejected - it could be caught in the earths gravity and be slowly spiraling towards us.

so maybe the real threat isnt actually a direct hit to us , but a direct hit to our moon

Well if you look at the moon it has some rather large crators on it already. I would assume that its been hit by a lot bigger than a .5

Not that this answers your question. But my logical mind says that it would take something about 1/20th the size of the moon to move it out of orbit. Maybe a little smaller.

I dunno, I can only speculate and cause I am not into math or physics, I can't honestly tell you other than to say, its a thought to ponder even for someone who doesn't fully understand these things

im going outside to throw chunks of bricks at some cheese to see what happens

I think if that happened the moon would turn Blood red

I'm still trying to remember what it was with Thundar the barbarian...

I think it was a comet that went between the earth and moon and caused the moon to fracture in half, that brought about the end of the modern world and created the world that cartoon is set in.

Thats what it was...yep...ok, I remember now. I know it doesnt have relevence to this thread anymore, but it was something that was bothering me because I knew it had something to do with the moon.

Mayeb in that other thread about the 2 meteors and the core of the dwarf star it might be better accepted.

"due to the lack of gravity"

There is no lack of gravity. The moon is being affected by the Gravity of the Earth and Sun, and also has its own Gravity. If a hypothetical 5 mile chunk of the moon broke off, it would most likely not escape the Moons gravity. Nor would it likely be in 1 piece. Either way, if it did escape the moons immediate gravitational field (as a solid mass or as a debris field), it would simply continue to orbit the Earth. At an orbit similar to that of the moon. Eventually getting soaked back up by the moon.

I think its fairly safe to assume that, as a rule, something hitting earth would be worse for us than the same object hitting the moon.

In various issues or Popular Science and Scientific american they have simulated and stated news about astrods. They are not as feared as they used to be, withthe dinosaur extinction most popular belief now being climate change. If something like that dosen't wipe out our race, I am sure the USA government will. lol.

I agree that it would have to be a fairly large mass to force a significant change in the moons orbit. There arn't many large rocks flying around out there like there used to be.

and Crash, I don't think that the earth would "loose its balance," because it isn't really balanced on anything.

There is no lack of gravity. The moon is being affected by the Gravity of the Earth and Sun, and also has its own Gravity.

ok , i meant it as a lack of gravity compared to our own - sorry

snip from site /

Suppose you weigh 100 pounds here on Earth. Would you like to know what you would weigh in different locations in space? Just look at this list.

Earth - 100 lbs
Moon - 17 lbs
Mercury - 38 lbs
Jupiter - 236 lbs
Pluto - 7 lbs
the sun - 2407 lbs
a white dwarf - 130,000,000 lbs
a neutron star - 14,000,000,000,000 lbs
in a spaceship far out in space - 0 lbs

/

now if an object of .5 miles across slammed into our moon at 30 000mph + it could project something out into space , the moon landers didnt hardly need any thrust to get out of the atmosphere , a size of a small house total lander compared to the size of a block of heights rocket.

i do realise that most of the rock would be pulverised to dust but if rocks hit mars and send them to earth and there is a possibility that rocks from earth have landed on mars then a large rock from the moon isnt out of the question is it.

i did say it was a long shot too by the way

Applaudes Kano, (for the first time)

I think Kano is right, it would be next to impossible for ejected to come off the moon in any sort of volume that would represent a danger to the earth. Even if fractured the Moons own gravitey would draw the chunks back together. It would be interesting to see the dramatic changes to the Moons structure though if a massive event like that happened.

As someone posted, a Blood red moon, due to the high friction forces and the possible, internal/external volcanizim at the surface.

It is obvious we are talking about the effects of the moon, but what about the gravitational/physical effects if you had a "pinball" situation. It is very, very, very^20 unlikley, but what if an object knocked the moon into the earth. not probable, but it is a different way of looking at it!

I know we have recorded meteroids hitting the moon, but what if it also effected the earth?

Oh now that is so very cool!! I've always wondered what a meteor hitting the moon would look like! THANKS for the link!!