Transcript Heliocentric ppt.

Heliocentric Solar System
BELLWORK:
What did the solar system do when it
wanted to have a party?
plan it!
Galileo Galilei
(1564 – 1642)
1610 “Siderius Nuncius” (The Starry
Messenger)
Used a handmade
telescope to view the sky.
"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.
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
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?
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
http://astro.unl.edu/classaction/animations/renaissance/venusphases.html
animation
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.
6
6
5
5
4
3
Sun
1
Earth
3
2
2
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.
4
1
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.
The apparent motion of the stars is a result of the Earth’s rotation
also, the Stars are much farther away than the Sun