by Pete » Thu Aug 02, 2007 9:26 pm
craterchains wrote:Pete wrote:craterchains wrote:How nieve it is to assume that ALL objects are traveling at hyper velocities.
Think about it.
And no, a planet or large moon can't "sneak up" on asteroids traveling at
almost the same velocity and gently sweep them up.
Guess then our solar system just couldn't have been formed by that very method? *coughs*
![Rolling Eyes :roll:](./images/smilies/icon_rolleyes.gif)
Planets and large moons weren't around before the formation of, well, planets and large moons
My intent was to explain why tossing rocks into sand, a process which easily produces noncircular "craters," is not analogous to the process behind the circular craters of moons and rocky planets. I was referring to the impossibility of the scenario in which a
massive body (say, a large moon) traveling at 1 km/s approaches a little asteroid traveling in the same direction at 1.001 km/s and gently scoops it out of space at a closing speed of 1 m/s. No, impact speed will
at least equal the moon's escape speed.
Over some range of escape speeds, impact energy is low enough to allow oblique crater formation; considering the noncircular craters that Chris pointed out, Dione is around the upper limit of that range.
[quote="craterchains"][quote="Pete"][quote="craterchains"]How nieve it is to assume that ALL objects are traveling at hyper velocities. :roll:
Think about it.[/quote]
And no, a planet or large moon can't "sneak up" on asteroids traveling at [i]almost[/i] the same velocity and gently sweep them up.[/quote]
Guess then our solar system just couldn't have been formed by that very method? *coughs* :roll:[/quote]
Planets and large moons weren't around before the formation of, well, planets and large moons :)
My intent was to explain why tossing rocks into sand, a process which easily produces noncircular "craters," is not analogous to the process behind the circular craters of moons and rocky planets. I was referring to the impossibility of the scenario in which a [i]massive[/i] body (say, a large moon) traveling at 1 km/s approaches a little asteroid traveling in the same direction at 1.001 km/s and gently scoops it out of space at a closing speed of 1 m/s. No, impact speed will [i]at least[/i] equal the moon's escape speed.
Over some range of escape speeds, impact energy is low enough to allow oblique crater formation; considering the noncircular craters that Chris pointed out, Dione is around the upper limit of that range.