Asteroid Density & Impact Rate - Earth vs Mars

[mersecske]

What is the ratio of asteroid impacts on the Mars to the same rate on the Earth?
I think it depends on the diameter of the planets (~ diameter^2),
and on the density of asteroids.
Ca we say something about this second factor?

 

[cepheid]

What is the ratio of asteroid impacts on the Mars to the same rate on the Earth?
I think it depends on the diameter of the planets (~ diameter^2),
and on the density of asteroids.
Ca we say something about this second factor?

Are you allowed to just assume that the meteor flux (i.e. the number arriving per unit area and per unit time) is the same for both planets? If so, does this factor matter when computing a ratio?

 

[mersecske]

Yes, but this is true? This is my question. This is a good estimation?
I don't think so,
I think, it depends on the asteroid belt dynamics, and the orbit of the planet.

But what is the observation?
For example which planet suffers the most asteroid impact?

 

[tony873004]

In Earth's favor is not only its larger diameter, but its higher mass. Asteroids that would have otherwise made a near hit to Earth or Mars will be pulled closer due to gravity. Earth has stronger gravity than Mars. The formula is Effective Radius = True Radius * sqrt(1+2GMv^2/True Radius), where M is the mass of the planet, and v is the asteroid's velocity at infinity. So to an asteroid traveling at 10 km/s, Earth's effective radius grows by 50%, while Mars' only by 12%.

But Mars is closer to the asteroid belt. It pretty-much defines the inner edge of the asteroid belt, and it does this by getting hit enough to sweep up any asteriods whose orbits cross Mars' orbit. So I imagine Mars gets hit a lot more often than Earth.

 

[cepheid]

But Mars is closer to the asteroid belt. It pretty-much defines the inner edge of the asteroid belt, and it does this by getting hit enough to sweep up any asteriods whose orbits cross Mars' orbit. So I imagine Mars gets hit a lot more often than Earth.

Sorry to the OP -- I don't have the answer to your question about how the meteor flux varies between the two locations. To add to what tony873004 said, I would also point out that Mars has a thinner atmosphere. Whether this makes a different or not, well I guess we'd have to be more quantitative to find out. But it is another point seemingly in favour of a higher impact rate on Mars.