Download Astronomy Unit Test – Chapter 21

Space Study Guide Answer Key
Use the diagram below to answer questions 1 & 2
1. Which point in the diagram below could produce a solar eclipse? A
2. Which point in the diagram below shows the position of a lunar eclipse? C
3. What is the cause of Earth’s Tides? Moon's gravity pulling on the oceans
4. The diagram shows the orbit of the moon around Earth. Between which two points will the moon appear to
change from a new moon to a quarter moon?
Between Q & T
5. Describe how Earth’s orbit around the sun determines the seasons of Earth? Earth’s axis tilts different
parts of Earth toward or away from the sun at different points in Earth’s orbit.
6. Why is it warmer near the Equator than the poles? It is warmer near the equator because the Earth
receives the most direct sunlight in this region.
7. Create a flow-map that shows the organization of the universe, from smallest to largest unit? star, star
cluster, galaxy, galactic cluster, universe
8. The H-R diagram is based upon which 2 criteria? temperature and brightness
9. The tilt of Earth on its axis affects Climate, Seasons, length of days.
10. The longest day of the year occurs on the summer solstice.
11. During which season does sunlight strike the Northern hemisphere as shown below?
summer
12. Research indicates that galaxies are moving away from Earth. What method allows astronomers to
determine this movement? measuring the wavelengths of radiation from these galaxies
13. Astronomers theorize that the universe began in an enormous explosion called Big Bang.
14. The color of a star is related to its temperature. Create a flow-map listing the colors that correctly identifies
the temperature of the stars in order from hottest to coldest? blue, white, yellow, red-orange, red
15. The diagram below shows the relative positions of Earth and the sun at a particular time of year. Describe
the length of day and night in the Northern and Southern Hemispheres at this time of year? Northern
hemisphere: days are longer than nights and Southern hemisphere days are shorter than nights
16. Star A and star B have the same absolute brightness, but star A is about twice as far from Earth as star B.
Describe the apparent magnitude of the stars? Star B is appears brighter than star A
17. Describe the reason for having a leap year? Every four years, the calendar is off by one day due to the
Earth’s revolution taking 365.25 days to revolve around the sun, so February 29th added to correct
the calendar.
18. The picture shows sand used to make a model of a galaxy. In the model, each grain of sand best represents
Stars.
19. Why is a month on the moon the same length as a day on the moon? The rotation and revolution take the
same amount of time.
20. About how old is the solar system? About 5 billion – 13 billion years old
Use the H-R diagram to answer 22 – 25.
21. Which supergiant is the brightest? Deneb
22. Which star is the coolest on the diagram? Van Maanen’s star
23. What category of star is Sirius B? white dwarf
24. Which giant is the brightest? Aldabaren
25. Predict what will happen when the sun runs out of fuel. It will become giant then a white dwarf.
26. What is used to classify stars? Brightness, Temperature, Composition, Color
27. At which phase of the moon could a solar eclipse occur? new moon
28. A star is twice as massive as the sun. How will its lifespan compare with the sun? Its lifetime will be
shorter than the sun.
29. Some astronomers discover a galaxy that contains only old stars. What type of galaxy is it likely to be?
elliptical
30. What does Hubble’s Law state? the farther away it is, the faster it is moving away from us.
31. Create a flow-map that properly sequences the formation of the solar system? solar nebula forms, nuclear
fusion begins in the sun, planetesimals form, planets form
32. A group of stars that form patterns in the sky is called constellation.
33. To express the distance between the Milky Way galaxy and other galaxies, the most appropriate unit of
measurement is the light year.
34. Which of the following properly sequences the life cycle of a massive star? Stellar nebula, red
supergiant, supernova, black hole.
35. The Milky Way galaxy would best be classified as Spiral galaxy.
36. Convert into scientific notation: 8,000,000,000,000
37. Convert into standard form: 8.543 X 1012
8 x 1012
8,543,000,000,000
38. The model below is set up to show how a lunar eclipse occurs. What is the greatest limitation of this model?
Comparative sizes and distances are inaccurate.
39. Which of the following star systems is an eclipsing binary?
1. What are the characteristics of UV waves?
Higher energy and frequency than visible light, prolonged exposure can damage cells, not vivible
to humans.
Use the diagram to answer questions 2 – 4.
2. In the diagram above, what is letter A
representing? Amplitude
3. What is the letter M representing? Crest
4. What is the letter C representing? Equilibrium Point
5. What are the characteristics of Gamma Rays?
C
Highest energy, highest frequency, produced by the
sun & other stars, very damaging to cells, used to
sterilize medical equipment by killing the germs.
6. What are the characteristics of particles in a transverse wave?
Move parallel to the direction that the wave moves. Cannot move through a vacuum or space.
7. List EM waves in order of longest wavelength to shortest wavelength?
Radio, microwaves, infrared light, visible light, ultraviolet light, x-rays, gamma rays
8. Infrared light is often used in reptile habitats. What explains how a reptile benefits from infrared
light?
Infrared light increases the body temperature of the animals.
9. What are the 7 types of electromagnetic waves?
Radio
Microwaves
Infrared light
Visible light
Ultraviolet light
x-rays
Gamma rays
10. What are the characteristics of particles in a longitudinal wave?
Move perpendicular (up and down) to the direction that the wave moves and move through
matter. They can move through a vacuum or space.