After reading others questions on gravity, I wondered: if a large meteor hit Mars and was powerful enough to push it off its current course for a significant distance, what would the effects on Earth be? Would we have different seasons, rotations faster/slower, or would the differential in gravity be insignificant?

Any insight would be helpful, just trying to figure out how fragile life is...

The path that mars follows is determined by the sun, if it were to explode into tiny pieces it would not effect the earth since the earths path is determined by the sun. The gravity of mars does not effect the earth. It would have to come very close to do so, thats a very big shunt.

If the moon was knocked slightly out of orbit or split in two, that would effect the earth and life.

Thats my simple opinion.

What would happen if the nearest star exploded, would the suns position change? Would that cause the orbits to change?

Thanks, and good question...

If the nearest star exploded, im pretty sure that we wouldnt be affected. Im too tired and lazy to look it up.

I think that if Mars were to get nudged it would effect Earth in a small but noticeable way. True the sun is the major factor in the Earths gravitational determination but other bodies also have an effect on each other. Also the new orbit would certainly be a concern. And I will have to agree with the nearest star having little or no noticeable effect on Earth.

I think we could be destroyed if a star went nova within about 20 light years of us. A supernova farther away could also do us in.

Within our own solar system, there are asteroids which could just about wipe us out if they hit the earth. Some people are now researching ways to protect ourselves.

To give you an idea of what can happen. In about 1812 (I think), there was a volcanic eruption far away from the US (indonesia, perhaps) which put a lot of dust and ash in the atmosphere. We got less sunlight and there were crop failures due to frost in July and August in various northern parts of the USA.

A big asteroid hitting the earth would be hundreds of times worse. It is believed that such an impact wiped out the dinosaurs and a lot of other species 65 million years ago. A bit enough one could do us in due to world wide crop failures and extreme cold for years, which could start another ice age. At best only 5-10% of us would survive.