So imagine you're looking at the world map. More specifically, the left half (when the world map is cut along a vertical line, so the half stretches from the left edge of a current world map to a longitude around France/Germany). I will refer to this half as half A. Ignore the other half (half B) for now.
Half A is essentially split into four land masses of land, which lie in the four corners of A. Imagine four North-America-shaped (but small enough to fit four) land masses in the four corners. These land masses are separated by oceans (but this is irrelevant).
Half B. This is where I'm unsure. Essentially, a really large meteorite came and it knocked off that half of the world. I mean, it didn't go all the way to the core, it just removed the crust. So Half B is essentially just extremely mountainous and jagged land which is half-flooded with the rest of the world's oceans.
My Question: Is this possible? Could the meteorite have caused all of this?
Don't worry about the climate or whether the planet is habitable. I've got that part sorted.
The world is the Earth in the 23rd Century, so the land masses have to roughly be the same shape (the shapes can't change drastically to make my planet possible).
The left half is what I'm referring to as half A and the right as half B. Even though my map suggests that there's only water in half B, there's a lot of mountainous land which is just flooded in places (but not completely). The shape of the land masses should be a bit like North America, but there's no other requirements. The border of halves A and B is roughly at the same longitude as France/Germany.