1. Do Now What is the geocentric model?
What did Copernicus contribute to astronomy?
What is the heliocentric model?
What did Galileo contribute to astronomy?
Who is Kepler?

2. Astronomy

3. How our Universe Formed
Theory of how the universe formed called the Big Bang Theory
Big Bang Theory – the universe formed from a massive expansion approximately 14 bya
The Universe is expanding and the visible edge is about 13.7 billion light years away

4. The universe began billions of years ago as a tiny dot that exploded into today’s huge system of stars and planets.

6. Cosmic background radiation
Support for the Big bang Theory
Red shifts
Cosmic background radiation
Radio signals coming from every direction in space.
Believed to be created by the big bang explosion.

7. The Expanding Universe
1929 – Edwin Hubble found that the universe is expanding
Estimated distances, relative brightness, Doppler red shifts

8. Dimmer galaxies had greater red shifts  farthest from Earth
Hubble’s Law: the more distant the galaxies have greater red shifts, therefore they are moving away at faster speeds.
Milky Way Galaxy…spiral shaped!

9. Note: Our solar system is part of a bigger system called a galaxy
Note: Our solar system is part of a bigger system called a galaxy. Our galaxy (Milky Way) is part of a bigger system called the universe
Milky Way Galaxy…spiral shaped!

10. Galaxies and Stars Galaxies – billions of star groups
more than 100 billion galaxies, each containing billions of stars
Milky Way Galaxy…spiral shaped!

11. So, how did our Solar System form?
The Nebular Theory – explains that solar system was formed from a rotating disk of dust and gas
Formed ~4.6 bya

12. 1.Solar System began as a giant ball of dust and gases (after the Big Bang)
Cloud flattened as it spun
around, forming an accretion disk.
►Sun formed in the middle from all
the heat in the middle of the disk
Cooling of the disk caused small
shapes to form
4. These cool forms combined to
make the 4 SOLID inner planets
The lighter material combined
farther away, forming the 4
GASEOUS outer planets

14. Pluto
Neptune
Uranus
Mercury
Saturn
Jupiter
Mars
Earth
Venus

15. How Earth’s Formation Affected Earth
Earth orbits the Sun following Kepler’s 3 laws of planetary motion
The path of each planet around the Sun is an ellipse
Equal areas are covered in equal time
The length of time it takes a planet to orbit the Sun is proportional to its distance from the Sun

16. Kepler (1571-1630) came up with these scientific laws and they are still used in Astronomy today!

17. 1st Law: Law of Ellipses
The path of the planets around the sun are elliptical in shape with the center of the sun being located at one focus
The shape of the ellipse is determined by the location of the two focus points!

18. 2nd Law: Law of Equal Areas
This law states that an imaginary line from the sun to a planet sweeps out equal areas in equal time intervals

19. Kepler’s 2nd Law of Planetary Motion

20. Are they the SAME?
The short wide glass is holding the SAME amount of water as the tall skinny glass!

21. Planet moves FASTER in orbit when CLOSE to the SUN, and SLOWER in orbit when FAR FROM the SUN
WHY?
GRAVITATIONAL PULL

22. Keppler’s 3rd Law

23. Do Now What does eccentricity measure?
Ms. Simmons observed the orbital path of Mars. From the data she collected, she found the focal point length to be 10 light years and the major axis length to be 22.5 light years. Find Mars’ eccentricity based on her observations.
Planet X has an eccentricity of and Plant Y has an eccentricity of Using these measurements explain the paths of these planets around the sun.

24. The Sun
The sun is at the center of our solar system. You may have learned that the planets orbit the sun, but in fact the Sun and planets orbit each other around the barycenter.

25. Sun consumes 600 million tons of H each second!
The Sun
Our Sun and all other stars produce their energy by a process called nuclear fusion
Fusion is when hydrogen atoms collide to make a Helium atom; this releases lots of energy
Sun consumes 600 million tons of H each second!

26. What is the Difference between Fusion and Fission?
Fission is the opposite idea…instead of building bigger atoms, you are breaking atoms apart
Nuclear Power Plants like McGuire Nuclear Station in Huntersville do this with Uranium

27. Energy Produced by the Sun
Most of what astronomers know about our universe is known from studying the light emitted from distant sources

28. Electromagnetic Spectrum
Visible light is just a small portion of the energy emitted by stars…what else is there?

29. Gamma Rays - are produced by violent nuclear explosions in space and are absorbed by our atmosphere…good thing, they are deadly to human cells!
X-rays - are also absorbed by Earth’s atmosphere, so NASA has to put x-ray telescopes into space
UV Rays - are mostly blocked by the ozone layer, but some can get through and cause sunburns!
Infrared Rays - cause the heat we feel from sunlight
Microwaves - easily move through atmosphere and are used in with satellites and GPS
Radio Waves - are used with huge telescopes to learn about the structure, composition, and motion of objects in space

30. The Electromagnetic Spectrum