Theoretically could an asteriod boil our water away?

Question

theoretically of course.... would it be possible for an asteroid to be massive enough that the impact into our atmosphere would boil away the water of the planet, or would the asteroid just be so massive it'd smash the planet into bits instead?

Answer 1

The heat of impact of a large asteroid could boil the oceans, vaporize the material of the Earth at point of impact, and blow some or all of the atmosphere completely away from the planet.

The Earth has a molten core, which means it is rather flexible and wouldn't be smashed to bits.

But a large asteroid could disrupt tectonic plates and cause earthquakes and volcanoes and significantly destroy much of the current surface.

Whatever was left of the asteroid would just become part of whatever was left of the Earth.

For an object to smash the planet completely, it would have to be as large as the moon.