The shuttle spacecraft does nort burn up at all when it does reenters the earths atmosphere, even of the heat. The reason is that there are all heat preventing tiles on the spacecraft from burning, and keeping the astronauts safe.
The Moon
Because the earth didn't have an atmosphere back then That answer is also right but their is another slip to it, the slip to it is that, their is a seasonal change in the atmosphere and if they didn't have a satellite the seasons wouldn't change, so that is also why we have satellites for electricity and the seasons...!
Meteor is a rock that crashes into our atmosphere. An asteroid would be the last rock object that crashed into our atmosphere, since it would wipe out life on the planet.
Studying earth's layer's is important. It gives us an insight about how the atmosphere works.
Sorry, but I do not understand "eaths". You should have spell-checked the question before posting it.
The Moon
It's what we live on.
the inner core
yes... it is the closest layer to the eaths surface
The mantle is the softest layer of the Earth.
Because they are subject to the process of erosion.
about 0.3 percent
Condensation transform vapors in liquid water.
Melted rock below the eaths suface is magma