How big would a meteor/comet need to be to knock earth out of its orbit?

Question

How big would a meteor/comet need to be to knock earth out of its orbit?

Answer 1

You mean completely pulverize ir? It's a combination of velocity and mass--- but something a little smaller  than Venus hitting Earth HEAD-ON-- would do it.--- Read this:

http://www.livescience.com/technology/de...

Answer 2

How far out of its orbit? 1 inch out? 1 mile out? A million miles out? All the way out of the solar system? I would think any meteor big enough to change the orbit by a million miles would completely destroy the planet from the impact. And a million miles is not much of a change in an orbit 93 million miles in size.

If you are thinking that some smallish nudge could upset the balance of forces so Earth were no longer orbiting at all, I must tell you that orbits don't work that way. Orbits are more stable than that. The physics and math describing how an orbit works is similar to that of a pendulum. If you bump it a little, it swings back and forth but never gets far from where it started. You are probably thinking an orbit is more like a pencil balanced on end, where any little push makes it fall over and it falls all the was as soon as it starts moving. Orbits aren't like that.

Answer 3

It would have to be an object larger than Mars to knock Earth out of its orbit.

"Even an impact by a Mars-sized body failed to dislodge Earth from its orbit around the Sun, although the impact probably did change our axis of spin to the present 23.5 degrees to the plane of the solar system. To escape the Sun, Earth would require a speed of 11,000 mph (5 km/s) over its orbital speed of 67,000 mph (30 km/s). It's difficult to envision a force that could accelerate the mass of Earth to such a speed and therefore improbable Earth will ever escape the Sun.

Earth may have been in a slightly different orbit before the Mars-sized body hit it but is unlikely to change much in the future. Earth's orbit has been relatively stable for over four billion years with little sign of change in its predictable orbits for at least the next five billion years. Although the Sun is shrinking slightly, astronomers believe this is a temporary contraction and has negligible effect on Earth's orbit."

Answer 4

It would take a planet bigger than Mars striking the Earth  to alter our orbit around the Sun significantly. Such an impact would of course sterilize the planet completely so if it were to happen, we'd be exterminated completely along with all other forms of life.

Answer 5

Big enough that we really wouldn't have to worry about

Answer 6

It would really depend on what angle it hit from. The collision between the Earth and the Mars sized planetoid that created our moon was moving in relatively the same direction so not much changed orbit wise. If, lets say, something the size of the moon were to hit us either coming directly to or from the sun than I think we would change orbits and become much more elliptical.

You and me would be dead before we could see it sadly =(

Answer 7

About a million times bigger than one that would destroy all life. One the size of Mars hit it 4 billion years ago, and we're still in orbit.

Answer 8

you could work this out yourself. please try it.

define "knock earth out of its orbit". it you define it to mean attaining escape velocity, you have your first number.

figure out how much momentum that is.

estimate how fast a colliding body might be traveling with respect to teh earth.

figure out how massive it would need to be to have that much momentum.

estimate its density and determine its size.

there's your answer.

Answer 9

It doesn't matter, an asteroid would destroy the earth into chuncks before knocking it out of orbit.

Answer 10

wouldn't really matter.. any comet/meteor that large would destroy us all, anyway, even if it didn't knock us out of orbit.