Mesosphere
No. The sky includes areas well within Earth's atmosphere, which are not considered part of outer space.
yes
It can be considered one, as in space exploration or space mission (meaning outer space). It may be a noun adjunct in the term space heater.Space can also be a verb (to separate by intervals) or a noun (area, volume, or outer space).
The layer of the atmosphere that is considered outer space is called the exosphere. This is the uppermost layer of the atmosphere, where the air is extremely thin and gradually transitions into the vacuum of space.
Well, we can be considered that, seeing as we are life on an outer space planet, but technically, since we are the only life, anything else that is found is considered an alien.
outer (as in "outer space")
Yes, the movie E. T. is science fiction, since E. T. is an alien that comes from Outer Space, and outer space is considered science fiction.
Exosphere (above about 600 miles).
There is no antonym for outer space.
outer (as in "outer space")
they built it in outer space
Light travels in vacuum but sound cannot. So, we can see solar flares but can't hear them. (Outer space can be considered to be vacuum)