1. Astronomy
Study of objects in space such as the Sun, stars, planets, comets, gas, & galaxies.
*Also, the Earth’s place in the universe.
Universe = everything that exists

2. Astrology is NOT science !!!
Disclaimer:
Astrology is NOT science !!!
There is currently no evidence that star positions affect human behavior or your future.
Go ahead & read your
horoscope but remember
that it is just entertainment!

3. Geo-centric Helio-centric
Earth-centered
view of universe
Sun-centered
view of solar system
C. Ptolemy
90-168
N. Copernicus
modern view of the solar system:
“the Sun” is a star
planets orbit the Sun

4. Cosmic Size and Distance

5. Cosmic Size and Distance

6. Cosmic Size and Distance

7. Cosmic Size and Distance

8. Galaxies = groups of billions of stars
there are more than 100 billion galaxies
they all have different shapes
Spiral
Elliptical
Irregular

9. The “Big Dipper” constellation is a pattern made of 7 stars
Cosmic Size
The “Big Dipper” constellation is a pattern made of 7 stars

10. Earth’s Seasons = caused by the tilted axis (23.5o)
Equinox = equal hours of daylight & darkness
Solstice = longest day & shortest day
Fall
Sep. 21
SUN
Dec. 21
Jun. 21
(shortest day)
(longest day)
Mar. 21
Spring

11. Earth’s Motions Winter – closest to the sun
Summer – farthest from the sun

12. Earth’s Motions Rotation Revolution
spinning of Earth from west to east on an axis
results in day / night
Earth makes one rotation in 24 hours
Revolution
Earth moves around the sun every 365¼ days

13. Equatorial Bulge The Earth is not completely round
There is a bulge at the equator because of rotation
Video Link

14. Earth’s Motions Precession
The change in direction of the northern axis
North star is different
Nutation
Slight wobble, or change, in Earth’s axis from 23.5°
Very slow movement due to the gravity of the moon

15. Kepler’s Laws 1st Law: orbital paths are ellipses (ovals)
Sun is at one focal point
Animation of Laws

16. Kepler’s Laws
2nd Law:
a planet sweeps out equal areas in equal times

17. Kepler’s Laws 3rd Law: T2 = d3 T= time of orbit
d = distance (avg) from the sun

18. A cloud of space dust or gas.
Nebula
A cloud of space dust or gas.

19. Nebular Hypothesis cloud of mostly hydrogen & helium A.
B. accretion disk A.
cloud of mostly hydrogen & helium B.
Started rotating & collapsing toward center because of gravity forming an accretion disk , also the Sun forms C.
rocky & metallic materials form as nebula cools D.
collisions of particles created asteroid-sized objects (protoplanets or planetesmals) E.
Sun = most dense object, nuclear fusion
Rock / Terrestrial planets = more dense, heavy material, closer orbit
Gas / Jovian planets = least dense, lighter material, farther orbit
A. nebula
C. cooling
D. protoplanets
E. solar system

20. Barycenter The point between two objects where they balance each other
The actual center of our solar system
The sun orbits around this point
Barycenter Video
Music :)

21. Energy Nuclear Fission Nuclear Fusion
The splitting of an atom to create energy
Produced in nuclear reactors
The fusion of two atoms to create energy
Happens within stars

22. Apple in the Dark
Imagine you are sitting at a table with a red apple in front of you. Your friend turns off all the lights. It is totally dark in the room. There are no windows in the room or crack around the door. No light can enter the room.
Write the statement you believe best describes how you would see the apple in the dark & explain your answer in a short paragraph.
You will not see the red apple, regardless of how long you are in the room.
You will see the red apple after your eyes have had time to adjust to the darkness.
You will see the apple after your eyes have had time to adjust to the darkness, but you will not see the red color.
You will only see the shadow of the apple after your eyes have had time to adjust to the darkness.
You will see only a faint outline of the apple after your eyes have had time to adjust to the darkness.

23. spectrum on:
p. 484 & 678

24. Electromagnetic Energy energy that travels in waves
spectrum on:
p. 484 & 678

25. The Electromagnetic Spectrum

26. Gamma Rays 1 cm X – Rays 2 cm Ultraviolet 3 cm Visible Light 4 cm
Infrared 5 cm
Microwaves 6 cm
Radio Waves 7 cm
spectrum on:
p. 484 & 678

27. How we “see” the universe:
this is a
RADIO TELESCOPE
we use this information to study galaxies

28. Lunar Eclipses Occurs during full moon phases
Do not see the moon because the Earth blocks light
Sun, Earth, moon in a line

29. Solar Eclipses Occurs when sun is blocked by the moon Sun, moon, Earth
If the moon is partially blocking the sun, a partial solar eclipse will occur

31. Eventually, matter cooled & condensed into galaxies, stars, & planets.
At one time, the universe was a hot, super dense ball smaller than an atom.
About 13.7 billion years ago, a rapid expansion occurred sending material in all directions.
This was the beginning of the universe.
Eventually, matter cooled & condensed into galaxies, stars, & planets.

32. Support for the Big Bang Theory
Red shifts
Cosmic background radiation (CBR)
Signals coming from every direction in space.
Radio, microwave, infrared, & X-rays.
Believed to be created by the big bang expansion.
Video

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

34. Hubble’s Law: galaxies are moving away from us (red-shift) at a speed that is proportional to their distance
the more distant the galaxy, the greater the velocity (moving away at faster speeds)

35. Doppler Effect wavelength changes if an object is moving toward or away from you
pitch gets higher
Whitney Houston !!!
BASS !!!
pitch gets lower

36. Doppler shifts from stars
Doppler Effect Song by Astrocapella

37. Cosmic Background Radiation (CBR)
The hypothesis that the universe has always been expanding (since the “Big Bang”) predicted (1948) that radiation produced from the first moment of expansion would permeate the universe.
In 1965 this radiation was discovered
In 2003 astronomers studying the CBR determined the universe is billion years old

38. Cosmic Speed Limit Speed of light = 300,000 km/s
Light-year = the distance light travels in one year (9,500,000,000,000 km)
The 2nd nearest star is 4.3 light years away (Alpha Centauri = triple-star system)

39. Incandescence: glowing from heat
Blue = hottest Red=coolest

40. Spectrum: light separated into component wavelengths
Learning from Light
What is white light?
What is a prism?
Is there light we can’t see?
What is ROY G. BIV?
Spectrum: light separated into component wavelengths
spectrum on:
p. 484 & 678

41. Types of spectra Sunlight, light bulbs
Sunlight that has traveled through our atmosphere
Hot gas

42. Practice Drawing Spectra!
Sodium