Outer space is much bigger than the solar system.
Yes, space is much bigger.
No, it's in your backyard. Of course it's in outer space!
That is the correct spelling of "outer space" (space away from Earth orbit, or away from the solar system).
One, because the whole outer space is one solar system.
astronomers
astronomy
The heliopause marks the outer boundary of our solar system. This is where the solar wind from the Sun meets the interstellar medium of space.
astronomers
the solar system, galaxies, and the univerese.
Astronomy is the study of outer space and the universe. This includes the solar system and earth in space.
Voyager I and II are pretty much on the edge of solar system.
Mainly astronomers. But cosmologists and astrophysicists will also be interested in outer space.