Some astronomers are likely to be good at DIY, but most would probably get a contractor in.
The best place for astronomers to build their telescopes is a cold, dry, and calm place. Astronomers identified a place in the Antarctic that they believe is the best place for an observatory. Read more about it at http://phys.org/news170932769.html.
They used the Pole star to find true north
Astronomers know because they have studied star patterns and placements and know when there has been a change between where there is a black hole and where there isn't one.
They dont
No. There are almost no astronomers that think Pluto is a planet. They know it's officially a dwarf planet.
By their gravitational effects.
Many astronomers, historians, regular people, and scientisis know about the planets in our Solar system.
Not really, the Babylonians and the Egyptians beat them to it.
There is no answer
Because people did not know what space was like back then. And astronomers were very important to make the decisions on what was really happening of there.
The question cannot be answered because we do not know who is foreign to you
Telescopes : e.g. The Hubble Telescope .