Chapter 18: Part C 9 (17-25)

_____ showed that planets move in elliptical orbits around the sun

_____ was one of the first astronomers to use a telescope to observe objects in space.

In about the time the moon takes to orbit the Earth, another ______ has passed.

An instrument that uses a set of lenses to focus light is a(n) _______.

The angle between a star and the horizon is the star's ________.

Each time the Earth rotates on its axis, another _____ has passes.

The line where the sky and Earth appear to meet is the ______.

Each _____ is a region of the sky.

Each time the Earth orbits the sun, another _____ has passed.