There are huge canal-like structures on mars, but i thought they where not made by water.There are no "huge canal-like structures on mars". There are however erosional features.
Also, you are presuming there is water everywhere where a meteor strikes.Nowhere have I ever presumed that. Instead, you appear to be engaging in a straw man argument.
And if a meteor where to hit ice-deposits, it would vaporize it, not melt it to a river :)Any energy raising the water ice on Mars to the melting point vaporizes it. The heating of the soil (as I wrote above) turns some of the ice to vapor, producing a temporary atmosphere in a limited area; this permits more of the water ice to melt into water, because there is sufficient atmospheric pressure.
You should try to drop an icecube on a plate of a few hundred degree Celsius. More spectacular then fireworks!And that has exactly nothing to do with anything discussed here.
You sure know how to be defensive in a discussion.
Those "erosional features" could not have arisen from the occasional rain. Some are deeper then the grand canyon.
Sure, there are no roots to hold soil together, but any comet-vapor-rain event would not occur every other day now, would it? We have been watching mars for a short while now and i haven't heard of it.