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Approximate diameter of Earth.
Shape of the Earth?
Percentage of the Earth covered in water?
Tilt of the Earth's axis?
The sky is BLUE because that part of the spectrum gets scattered by . . .
Main cause of optical pollution?
Position north or south of the Equator.
Position east or west of the Greenwich Meridian.
The imaginary line in the sky between the observers Pole and Zenith?
The point in the sky directly above the observer.
Type of telescope that collects light, 'bounces' it off a concave mirror, brought to a focus by a secondary mirror further up the tube.
Why are larger telescopes 'reflectors' rather than 'refractors'? Because Refractors suffer from . . .
Lens sagging and colour aberration.
What can Mobile phone signals and telecommunications affect?
There is less atmosphere to obscure viewing; good, dry weather; fewer clouds and remote to decrease light pollution.
Why are observatories built in the mountains?
What is Earth's atmosphere transparent to?
Visible light, microwaves and some radio waves.
Why are X-Ray, infrared and ultraviolet observatories located on spacecraft?
Because that part of the spectrum gets absorbed by the Earth's atmosphere.
Name of the magnetic field around the Earth that traps solar particles.
Van Allen Belts