The sun is part of the galaxy called...

There are ___ of galaxies in the universe.

The science that studies the universe.

The Greeks used instruments such as the astrolabes to track the positions of the ____.

Greeks used the basics of ___ to measure the sizes and distance of the sun and the moon.

This Greek philosopher concluded that the Earth is round.

First successful attempt to establish the size of Earth was by

Best known for his star catalog.

Model where th earth is the center of the universe.

First Greek to believe in a sun centered universe.

Sun centered universe.

Presented a model of the universe that was called the Ptolemaic system.

First great astronomer to emerge after the Middle Ages and was convinced that the Earth was actually a planet.

This astronomers observations, especially of Mars, were far more precise than any made previously.

Discovered three laws of planetary motion

The path of Mars around the Sun is called...

Most important contributions were his descriptions of the behavior of moving objects.

Galilei's 1st observation.

The concept that a moving object will continue to move at a constant speed and in a straight line.

The first to formulate and test the law of universal gravitation.