The study of space

The Solar System

Part 1: Who came up with all of this

information?

Thinking like a scientist

• What if I were to tell you that the sky was

actually green and grass was blue…
– What would you say?
– How could you prove you were right and I was

wrong

Open Ended

Convince me the sky is not green and the grass is not blue

But first…some vocabulary

• Solar System- sun and all of the celestial

bodies that orbit the sun

• Heliocentric- sun centered- planets orbit the

sun

• Geocentric- earth centered- planets, sun, and

moon circle the earth

Where did we get these ideas

Aristotle

• Greek astronomer
• Geocentric model
• Decided that if the solar system was

heliocentric then the position of the stars
would change
– Parallax= apparent displacement of an object

when viewed from a different location

Ptolemy

• Astronomer, geographer,

mathematician

• Egyptian
• Geocentric

– Earth does not move
– Planets orbit in perfect

circles around earth and
orbit within their circle

• Made way for current

theory

Kepler

• Develop current orbit theory

– 3 Laws

• Orbits are ellipses
• Planets move faster in orbit when closest to sun
• Distance from the sun relates to how long it takes a

planet to orbit

Copernicus

• Polish Astronomer
• Heliocentric

– Sun was at then center
– Still believed the earth

didn’t move

– All planets revolved in

perfect circles around
the sun

Galileo

• Made improvements to the telescope

– Able to see Jupiter’s moons

• Helped to prove that Copernicus was correct

– Viewed that Venus went through phases like

Earth’s moon.