Astronomy
Mainly astronomers. But cosmologists and astrophysicists will also be interested in outer space.
Nothing. That is why they call it outer space. the only things that are out there are stars, rocks, planets and light and darkness
Exospace or "E" Space as its communally referred to is the space outside of normal space or as we call Outer Space in the known Universe
Astronomers
In theory, it can't. Astronomers consider time and space to be different sides of the same function - they call it "timespace". As long as time continues, space will continue to expand.
Strategic Defense Initiative.
Aliens, E.T., extra terrestrials. There are many names.
Astrophysicist, astronomer, astrologer, trekkie to name a few.
No living being - plants or otherwise - have yet been discovered in outer space; much less living beings that move through outer space!
Robot
Astronomy
A stone which enters the Earth's atmosphere from outer space is called a meteor.