1. TAKS REVIEW
CH. 13 – THE UNIVERSE

2. How is the Universe organized?
GALAXIES
SOLAR SYSTEMS
PLANETS

3. The Universe Consists of EVERYTHING (matter, energy, space)
Scientists believe it began as a “BIG BANG” and continues to EXPAND

4. Light Year Is a measure of DISTANCE (NOT TIME) in space
Equal to the distance light could travel in one year
EX: If a star is 4 light years away, traveling at the speed of light (186,000 miles/sec), it would take you 4 years to get there.

5. STARS Heated balls of GAS Mostly made of HYDROGEN and HELIUM
Will continue to “shine” as long as gas is available
NUCLEAR FUSION – nuclei join together

6. STAR FORMATION Form from NEBULA – clouds of gas (H) and dust
gravity pulls gas and dust in
nuclear fusion of H atoms to He
energy is released (SHINE)
H + H He

7. STAR – LIFE CYCLE Runs out of Hydrogen Expands – RED GIANT
Collapses to a DWARF or BLACK HOLE
***depends on the original MASS of star***

8. GALAXIES Made of stars, nebulae, black holes, solar systems, etc.
3 shapes
IRREGULAR SPIRAL ELLIPTICAL
MILKY WAY

9. Gravity FORCE that pulls objects together
GRAVITY as objects move CLOSER
GRAVITY as objects MASS increases
GRAVITY keeps:
Planets in orbit
Comets in orbit
Moon in orbit
GRAVITY

10. Earth Movement ROTATION – spin on axis = 1 day (RO”DAY”TION)
REVOLUTION – movement around
sun = 1 year
TILT – 23.5° from perpendicular = causes
SEASONS

11. SEASONS
Caused by TILT of Earth; opposite in NORTHERN and SOUTHERN hemispheres because only one can be tilted toward the sun at a time
Hemisphere tilted TOWARD sun receives MOST DIRECT sunlight = HOTTER

12. Seasons cont.
Hemisphere tilted AWAY from sun receives LESS DIRECT sunlight = COOLER
SPRING and FALL – NEITHER hemisphere is tilted toward/away from sun; light hits equally on both hemispheres

13. Lunar Phases Moon phases depend on position of Earth, sun and moon
Moon phases depend on position of Earth, sun and moon
The phase Earth sees depends on where the moon is in relation to the sun
The sun can only light up 1 side of the moon
WAXING – getting BIGGER (RIGHT)
WANING – getting SMALLER (LEFT)

14. Label the phase names below:

15. 1) When the Earth is at its greatest distance from the Sun, its Northern Hemisphere is tilted toward the Sun, as shown in the drawing below.
What season takes place in the Southern Hemisphere at this time?
A. Spring C. Summer
B. Autumn D. Winter

16. 2) The time required for the moon to show a complete cycle of phases when viewed from Earth is –
A. 24 hours C. 29 days
B. 7 days D days

17. 3) The daily path of the Sun, as viewed from the Earth, changes with the seasons because –
A. Earth’s axis is tilted
B. Earth’s distance from the Sun changes
C. The Sun revolves
D. The Sun rotates

18. 4) The moon’s phases can be observed from Earth because the moon –
A. Reflects the Sun’s light
B. Acts as a nuclear reactor
C. Fuses hydrogen nuclei into helium
D. Casts a shadow on the Sun’s
surface

19. 5) The shaded portion of the map below indicates areas of night, and the unshaded portion indicates areas of daylight.
What day of the year is represented by the map?
A. March 21 C. December 21
B. June 21 D. September 21

20. 6) On which two dates do all locations on Earth have equal hours of day and night?
A. September 23 and December 21
B. December 21 and March 21
C. March 21 and June 21
D. March 21 and September 23

21. 7) Which group is arranged in order from smallest to largest?
A. Earth, moon and Sun
B. Universe, Sun, galaxy
C. Milky Way, Sun, Earth
D. Planet, galaxy, universe

22. Use the diagram below to answer the following question.
8) Which of the following is the next phase of the moon? A. B. C. D.