8Th Grade Science Earth's Rotation

Front 1

What is a planet?

Back 1

1.An object of LARGE size that orbits around a star.
2. Our planet (Earth) orbits an average star (SUN).

Front 2

In what 2 ways do all planets move?

Back 2

1. Planets Revolve
2. Planets Rotate

Front 3

What does it mean when we say a planet revolves?

Back 3

1. It moves around another object.
2. The earth revolves around the sun.

Front 4

What does it mean when we say a planet rotates?

Back 4

1. It spins on an imaginary line known as an axis.

Front 5

Aristotle (300 BC) & Ptolemy (140 AD)

Back 5

Ancient Greek philosophers who developed the idea of a "Geocentric" universe.

Front 6

Nicolaus Copernicus

Back 6

The first person to propose the idea of a "Heliocentric" Solar System

Front 7

Galileo (1600's)

Back 7

1) He was able to provide enough evidence to convince people that the "Heliocentric" Solar System was correct.
2) He was arrested for his views and publishings.

Front 8

Geocentric

Back 8

Geo=Earth
Earth is at the center. Planets revolve around the earth. This idea was developed by Aristotle in 300 BC.

Front 9

Heliocentric

Back 9

Helio=Sun
The Sun is at the center. Other planets revolve around the Sun.
This idea was proposed by Nicolaus Copernicus in 1543.

Front 10

What piece of technology did Galileo use to observe objects in the sky?

Back 10

A telescope

Front 11

What did Galileo discover with his telescope about the planet Jupiter to support the Heliocentric (Sun as center) system?

Back 11

Galileo saw four moons revolving around Jupiter. Therefore, not everything in the sky revolved around the Earth.

Front 12

What did Galileo observe when he looked at Venus with his telescope?

Back 12

Venus goes through phases similar to those of the Earth's moon. The phases of Venus could not be explained if Earth were at the center of the system of planets. Therefore, the planets must be moving around the sun.

Front 13

Tycho Brahe (1581-1601)

Back 13

1. During 1581-1601 he & his team carefully tracked the positions of the moon, planets, & about 1,000 stars.
2. He kept detailed notes of his work.
3. In 1601, upon his death, his notes were passed down to one of his assistants-Johannes Kepler.

Front 14

Johannes Kepler (1601-1619)

Back 14

1. Using Brahe's notes and his own observations, he made important discoveries about the orbit of each planet.
2. He learned about the shape, size, and speed of each planet's orbit.
3. His discoveries are known as "Kepler's 3 Laws of Planetary Motion".