What happen when earth got hit by rock that size of a moon

When the earth is hit by a rock the size of a moon, there would a big impact crater that would result from this collision.

The impact will send shock waves outward to every part of the earth and this will disrupt every life activities on our blue planet.

Frictional heating as a result of the collision will cause surging earth temperature. This is a disruptive phenomenon. The earth's atmosphere will receive blown dust from the surface. This can lead to attenuation of global weather. A huge impact crater gulping a big part of the earth will result from the collision. Almost all life on earth will become extincted.