Heliocentric Solar System Bellringer: Off of what evidence was the Geocentric Model of the Solar System based? What motion challenged the idea and how was it explained? Heliocentric Solar System

BELLWORK: What did the solar system do when it wanted to have a party? plan it!

Galileo Sun: Moon: Jupiter: Venus: Copernicus With a telescope: Sun

"Eppur Si Muove“ "(And, yet it moves!") Galileo Galilei (1564 – 1642) 1610 “Siderius Nuncius” (The Starry Messenger) Used a handmade telescope to view the sky. With his telescope and discoveries, Galileo provided the EVIDENCE for Copernicus’ Heliocentric model. "Eppur Si Muove“ "(And, yet it moves!")

Galileo Galilei (1564 – 1642) The Moon has mountains, valleys, craters, just like Earth! So… we (Earth) is not so special. The objects in the solar system are similar. This went against the ruling Church’s view that man (who was made by God in his image) and thus Earth was the center of all things.

Sunspots on the Sun moved across the face of the Sun, so….. Galileo Galilei (1564 – 1642) Sunspots on the Sun moved across the face of the Sun, so….. What is the sun doing? The sun must be rotating, spinning! So….. Does the Earth also spin, rotate? SUNSPOTS

Galileo’s 4 Moons – Io, Europa, Calisto, & Ganymede Jupiter Has Moons! Galileo’s 4 Moons – Io, Europa, Calisto, & Ganymede Big Jupiter has several moons orbiting it! So….. Could the Sun have planets orbiting it too? Galileo was constructing evidence to prove the heliocentric model

More evidence… With his telescope, Galileo observed that Venus has phases, just like our moon! Over the months of the year, Venus can be observed changing in size and going through phases

Why does the SIZE of Venus change through out the year? On your white boards, diagram the Sun, Venus and Earth Show the motion to describe the Earth observing phase on Venus

http://astro. unl. edu/classaction/animations/renaissance/venusphases http://astro.unl.edu/classaction/animations/renaissance/venusphases.html animation Galileo and his discoveries

Retrograde motion of Mars: Galileo Copernicus Mars Earth Sun Retrograde motion of Mars:

Nicholas Copernicus (1500 AD) (a thousand years after Ptolemy In Europe) The HELIOCENTRIC Model “De Revolutionibus Orbium Coelestium”

A New and Improved Model Using Galileo's observations with the telescope, Copernicus tried a different model, placing the SUN in the CENTER with the planets orbiting around it. HELIOCENTRIC Let’s see if it explains retrograde motion.

Copernicus Explains Retrograde Motion Planet's apparent path around sky. Fixed Stars 6 Sun 6 5 5 4 4 3 3 2 2 1 Earth 1 Mars orbit Fast Earth overtakes slower outer planets so they appears to slow down, move in reverse, and then move forward again with respect to the fixed stars.

“On the Revolution of the Heavenly Spheres” Retrograde Motion was much simpler to explain If….. Earth is NOT the center of “everything.” The SUN is at the center of the solar system Any observed movement of the Sun is due to Earth’s revolution (orbit) and rotation about the Sun. Key point of his findings. He didn’t publish his book until his death for fear of repercussions from the Church The apparent motion of the stars is a result of the Earth’s rotation also, the Stars are much farther away than the Sun

Sun Earth Mars