1. The Big Bang and Early Astronomers

2. A SCIENTIFIC THEORY is an explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation.scientific method repeatedly tested and confirmedobservation experimentation Theories can be modified or rejected as more evidence is gathered Theories are testable ASTRONOMY: The scientific study of the universe and the objects in it, including stars, planets, nebulae, and galaxies. Astronomy deals with the position, size, motion, composition, energy, and evolution of celestial objects. Astronomers analyze not only visible light but also radio waves, x-rays, and other ranges of radiation that come from sources outside the Earth's atmosphere.

3. Not So BIG, No Bang! Big Bang Theory: state that approximately 15 billion years ago, the universe began expanding out from a Primeval atom due to some type of large energy release like an explosion. It was proposed by Georges Lemaitre, French physicist Greeks were the first people to use mathematics to interpret the night sky At the time; they could only see 5 planets What were they?

5. Nicoles Copernicus After the fall of the Roman Empire, much of the knowledge of astronomy was lost. Copernicus was a Polish astronomer who made the next big discovery about the motion of our Solar System. Copernicus moved the Earth form the center of the solar system and replaced it with the Sun. The movement of the planets as seen form Earth is due to the rotation of Earth. Geocentric : having the Earth as the center of the solar system or universe Heliocentric: having the Sun as the center of the solar system

6. Kepler Kepler used calculations to explain how the universe moves. He proposed that the planets revolve around the Sun which is offset from the center; and that they do so in an elliptical pattern.

7. Galileo Used technology to observe the planets, stars, and solar system He developed a more accurate telescope which allowed him to see the planets more clearly. He observed that Venus went through phases like our moon What could this mean?