A question I have regarding to water planets and asteroids

[Austritistanian]

So let's say you have a large water planet, where 50% of it is made up of water, surely the ocean floor would be thousands of kilometers deep. Now, let's say you have an asteroid, dashing at incredible hihg speed, and it's going to graze the water planet, just diving a few hundred kilometers deep into the planet's ocean, before coming out on the other side(?). I've put a picture below to demonstrate what I'm talking about

So, as the asteroid grazes the planet, will it pass through, or will it sink down slowly, without causing a cataclysmic explosion ALA every end of the world movies ever?

(It will cause a tsunami that's for sure)

[felipe]

i think it would hit the planet like a brick wall because even at orbital speed on the surface of our planet (if the object dont have something that help's it to make a "hole" in the atmosphere) it would hit the air like a brick wall too

[Darvince]

that doesn't say what its trajectory would be though

[atomic7732]

i think pretty much if it hits the water, water is too dense and the collision will slow the object down and cause it to collide completely

there have been some objects that have skimmed earth's atmosphere and continued off into space, and that's probably the limit. an object can probably pass through some portion of the atmosphere and escape without colliding, but probably nothing as dense as water or denser

[Physics_Hacker]

To pass through that much water I'm sure an asteroid would have to have an extremely high velocity, we're talking so high this would have to occur in the inner portion of a system where orbital speeds are high and the asteroid would have to have a cometlike orbit to achieve such a high velocity. Otherwise, friction with the water would slow it down to the point that it would probably just sink down to wherever the water is compact enough to become Ice II. Though I will say, with the right velocity, angle and density and minerals of/in the water, maybe an asteroid could be slowed enough to be caught in a low orbit, though I'm sure the "keyhole" for such a scenario would only be on the order of feet across if not less.

[atomic7732]

it would have to be an interstellar object for sure, an object falling from infinity passing the surface of the parent star would not be going fast enough to penetrate through the ocean of a water planet

i think another problem is, even if an object was going "fast enough" to do it, it would break up on impact, and smaller objects are affected by drag (through the atmosphere or water, doesn't matter) more than larger ones due to their cross-section to mass ratio, this is why comet tails are pushed away from the sun due to solar wind, while the comet itself isn't (well... it is, but just a lot lot less)

that's not to mention the energy and mass that the object would lose from colliding with the water and burning up in the atmosphere (and water)

so i don't think it's even physically possible (unless you had an ideal indestructable object)