1. What Lies Beyond

2. Warm Up Questions
CPS Questions (1-2)
Chapter 4, Lesson 2

3. Lesson Overview Other Galaxies and Their Classifications
Five Types of Space Objects
The Electromagnetic Spectrum
The Big Bang Theory
Chapter 4, Lesson 2

4. (Note to teacher: Use “Pick a Student” button in CPS)
Quick Write
What other example can you give, either in history or from your own life, of an important discovery made on the search for something else?
(Note to teacher: Use “Pick a Student” button in CPS)
Chapter 4, Lesson 2

5. Other Galaxies and Their Classifications
Edwin Hubble divided galaxies into three major groups
Spiral
Elliptical
Irregular
Chapter 4, Lesson 2
Courtesy of California Institute of Technology

6. The Characteristics of Spiral Galaxies
A barred spiral galaxy is a spiral galaxy in which the spiral arms come from the ends of a bar through the nucleus, rather than from the nucleus itself
A lenticular galaxy is a galaxy with a flat disk like a spiral galaxy, but with little spiral structure, and a large bulge in the nucleus
Chapter 4, Lesson 2
Courtesy of Todd Baronson NOAO/AURA/NSF

7. The Characteristics of Elliptical Galaxies
An elliptical galaxy is a galaxy with a smooth spheroidal shape
Science classifies elliptical galaxies according to how they appear from Earth, from round to very elongated
Chapter 4, Lesson 2
Courtesy of NOAO/AURA/NSF

8. The Characteristics of Irregular Galaxies
An irregular galaxy is a galaxy of irregular shape that cannot be classified as spiral or elliptical
The Magellanic Clouds are usually classified as irregular galaxies
Chapter 4, Lesson 2
Courtesy of NOAO/AURA/NSF

9. The Brightness, Luminosity, and Motions of the Stars
Apparent magnitude is a measure of the amount of light received from a celestial object
This measure contrasts with luminosity – the rate at which electromagnetic energy is emitted from a celestial object
Proper motion is the term for the angular velocity of a star as measured from the Sun
Proper motion is opposed to observed motion that is due to Earth’s movement
Chapter 4, Lesson 2

10. Optical Doubles and Binary Star Systems
Optical double is two stars that, from Earth, appear to be very close but are not actually gravitationally bound
Chapter 4, Lesson 2

11. Interstellar Clouds and Nebulae
Fluorescence is the process of absorbing radiation of one frequency and re-emitting it at a lower frequency
An emission nebula is a cloud of interstellar gas receiving ultraviolet radiation and fluorescing
Chapter 4, Lesson 2

12. Interstellar Clouds and Nebulae, cont.
A reflection nebula is a cloud of interstellar dust that becomes visible because it refracts and reflects light from a nearby star
A dark nebula is an interstellar molecular cloud whose dust blocks light from stars on the other side of it
Chapter 4, Lesson 2
Courtesy of Hubble Heritage Team (STScl)/NASA

13. The Discovery of Pulsars
Jocelyn Bell stumbled upon pulsars in 1967 while searching for quasars
A pulsar is a pulsating radio source with a regular period, between a millisecond and a few seconds, believed to be associated with a rapidly rotating neutron star
Chapter 4, Lesson 2
Courtesy of NASA

14. Theories About Dark Matter in Space
Missing mass is the difference between the mass of clusters of galaxies as calculated from Keplerian motions and the amount of visible mass
Dark matter — matter that can be detected only by its gravitational interactions
Dark energy — an exotic form of energy whose negative pressure speeds up the expansion of the universe
Chapter 4, Lesson 2

15. The Types of Electromagnetic Waves
The Electromagnetic spectrum is the entire array of electromagnetic waves
Celestial objects emit waves up and down the spectrum
Scientists learn a great deal from the invisible radiation emitted by celestial objects
Chapter 4, Lesson 2

16. The Types of Electromagnetic Waves, cont.
Chapter 4, Lesson 2

17. The Atmospheric Absorption of Wavelengths
Visible light and part of the radio spectrum can cut through the atmosphere
The atmosphere blocks most of the electromagnetic spectrum
Chapter 4, Lesson 2

18. The Big Bang Theory
The big bang is the theoretical initial explosion that began the expansion of the universe
In 1948 scientists theorized that cosmic microwave background radiation (CMB) would be striking the Earth from all directions but that it should be very faint
Chapter 4, Lesson 2

19. Other Evidence for the Big Bang Theory
The sky is dark at night because the universe is finite
A finite universe doesn’t have enough stars to light up all of space
The observed proportions of light chemicals are consistent with a process of nuclear fusion in the first few minutes of a hot young universe
Chapter 4, Lesson 2

20. Learning Check CPS Questions (3-4)
Chapter 4, Lesson 2

21. Activity 1: What Lies Beyond Puzzle
Use your textbook to complete the crossword puzzle.
Chapter 4, Lesson 2

22. Activity 2: Space Objects
Review information about your assigned space object in the textbook (pages ) and other materials, if available
As a group prepare a five-minute presentation about your topic
Chapter 4, Lesson 2

23. Activity 3: Vocabulary Academic Challenge
“Family Feud” style activity
Name the correct vocabulary word
Each correct answer is worth 100 points
Chapter 4, Lesson 2

24. Technology Enrichment: Final Shuttle Mission to Hubble
Using the website provided, work in small groups to learn more about the final shuttle mission to repair the Hubble Telescope
Chapter 4, Lesson 2

25. Review
Edwin Hubble divided galaxies into three major groups: spiral, elliptical, and irregular
There are five types of space objects – stars, binary star systems, clouds and nebulae, pulsars, and dark matter
The electromagnetic spectrum is the entire array of electromagnetic waves
The big bang is the theoretical initial explosion that began the expansion of the universe
Chapter 4, Lesson 2

26. Review Questions CPS Questions (5-6)
Chapter 4, Lesson 2

27. Summary Other Galaxies and Their Classifications
Five Types of Space Objects
The Electromagnetic Spectrum
The Big Bang Theory
Chapter 4, Lesson 2

28. Next… Done – What Lies Beyond Next – Why Explore Space?
Chapter 4, Lesson 2
Courtesy of NASA/JPL