Name______Class______Date______
Ch 18 Directed Reading (Pg. 554 - 570)
Section 1: Astronomy: The Original Science
Circle the letter of the best answer for each question.
1.______What did ancient cultures use to mark the passage of time?
a. stars, planets, and moon
b. stars
c. planets
d. sun and moon
2.What science did the study of the night sky become?
a. astrology c. astronomy
b. cosmology d.physiology
OUR MODERN CALENDAR
Read the description. Then, draw a line from the dot next to each description to the matching word.
3.how long the Earth takes to orbit once around the sun4.roughly how long the moon takes to orbit once around the Earth
5.how long the Earth takes to rotate once on its axis / •
•
• / a.day
b.month
c.year
WHO’S WHO OF EARLY ASTRONOMY
Circle the letter of the best answer for each question.
6.What did most early astronomers think made up the universe?
a. sun and planets
b. sun and Earth
c. sun, moon, and Earth
d. sun, moon, and planets
Directed Reading B continued
Circle the letter of the best answer for each question.
7.How did early astronomers learn about the universe?
a. They learned from history.
b. They discovered almost everything with their eyes and minds.
c. They used calendars.
d. They made good guesses.
Ptolemy: An Earth-Centered Universe
8.What did Ptolemy think was at the center of the universe?
a. Earth c. moon
b. sun d. other planets
9.What did Ptolemy think moved around the Earth?
a. sun and other planetsc.only the moon
b. only stars d. only the sun and moon
10.What did Ptolemy predict better than any other astronomer of his time?
a. the number of planets
b. the sizes of the planets
c. the atmospheres of the planets
d. the motions of the planets
11.For how many years did most people believe Ptolemy’s theory?
a. about 100 c. over 1,500
b. about 500 d. over 5,000
Copernicus: A Sun-Centered Universe
12.What did Copernicus think was at the center of the universe?
a. Earth c. moon
b. sun d. other planets
Directed Reading B continued
Circle the letter of the best answer for each question.
13.What did Copernicus think moved around the sun?
a. only Earth and the moonc.only the moon
b. Earth and other planetsd.only the moon and stars
14.What happened after Copernicus’s theory was accepted?
a. Major changes in science and society took place.
b. There was less interest in science.
c. There was less interest in culture.
d. There was less interest in the Earth and other planets.
Read the words in the box. Read the sentences. Fill in each blank with the word or phrase that best completes the sentence.
observations / telescope / gravity / ellipticalTycho Brahe: A Wealth of Data
15.Tycho Brahe recorded precise ______of planets and stars.
Johannes Kepler: Laws of Planetary Motion
16. Johannes Kepler said that planets revolved around the sun in ______orbits.
Galileo: Turning a Telescope to the Sky
17. Galileo was one of the first astronomers to use a(n) ______to observe objects in space.
Isaac Newton: The Laws of Gravity
18. Isaac Newton showed that ______keeps moons and planets in orbit.
Directed Reading B continued
modern ASTRONOMY
Circle the letter of the best answer for each question.
Edwin Hubble: Beyond the Edge of the Milky Way
19.Who proved that the Milky Way was not the only galaxy?
a. Newton
b. Hubble
c. Galileo
d. Copernicus
20.What did Hubble’s work prove about the size of the universe?
a. It’s bigger than our galaxy.
b. It’s smaller than our galaxy.
c. It’s shrinking.
d. It’s staying the same.
Section 2: Telescopes
Circle the letter of the best answer for each question.
1.What does a telescope gather from objects in space?
a. optical radiation c.electrical radiation
b. magnetic radiation d.electromagnetic radiation
2.What does a telescope do with electromagnetic radiation?
a. collects and concentrates itc.collects and expands it
b. collects and dissolves itd.collects and breaks it
Optical Telescopes
3.What kind of light does an optical telescope collect?
a. visible light c.ultraviolet light
b. invisible light d.ultrared light
Read the words in the box. Read the sentences. Fill in each blank with the word or phrase that best completes the sentence.
magnifies / eyepiece / collects / objective4. The simplest optical telescope has a(n) ______lens and a lens in the ______.
5. The objective lens ______light and forms an image.
6. The lens in the eyepiece ______the image made by the objective lens.
Refracting Telescopes
Circle the letter of the best answer for each question.
7.What does a refracting telescope use to gather and focus light?
a. lenses c. mirrors
b. prisms d. metal disks
Reflecting Telescopes
8.What does a reflecting telescope use to gather and focus light?
a. lenses c. mirrors
b. prisms d. metal disks
9.What is one advantage of reflecting telescopes?
a. They gather less light.
b. They use smaller mirrors.
c. They weigh less.
d. Flaws in the glass don’t affect the light.
10.What can a reflecting telescope do that a refracting telescope cannot do?
a. collect light
b. focus all colors to the same point
c. touch up images
d. send images via e-mail
Very Large Reflecting Telescopes
11.What do very large reflecting telescopes use to collect and focus more light?
a. many linked mirrors
b. a very large mirror
c. a huge objective lens
d. a very large eyepiece
Optical Telescopes and the Atmosphere
Circle the letter of the best answer for each question.
12.What affects the light that a telescope on the Earth gathers?
a. temperature
b. location
c. Earth’s atmosphere and light pollution
d. Earth’s atmosphere and noise pollution
13.How does the Earth’s atmosphere affect the light a telescope gathers?
a. It blurs starlight. c.It breaks light apart.
b. It makes it darker. d.It changes its colors.
14.What is a good place on Earth to put a telescope?
a. in a valley c. on top of a mountain
b. by a lake d. near a city
Optical Telescopes in Space
15.Why do scientists put telescopes in space?
a. to be able to detect very large objects in space
b. to avoid interference from the Earth’s atmosphere
c. to allow less light to be collected
d. to allow more light to be collected
the electromagnetic spectrum
16.Who proved that visible light is part of the electromagnetic spectrum?
a. Edwin Hubble c.James Clerk Maxwell
b. Galileo d. Isaac Newton
Directed Reading B continued
Circle the letter of the best answer for each question.
17.What is the electromagnetic spectrum made of?
a. all the wavelengths of electromagnetic radiation
b. magnetic metals
c. waves of gamma rays
d. bands of heat
Detecting Electromagnetic Radiation
18.What is each color of light?
a. a different magnetic element
b. a different wavelength of electromagnetic radiation
c. a different type of gamma rays
d. a different type of radio waves
19.Which of the following is NOT a type of electromagnetic radiation?
a. X rays c. infrared light
b. gamma rays d.black holes
20.What does the Earth’s atmosphere do to most electromagnetic radiation?
a. melts it c. blocks it
b. absorbs it d. freezes it
21.Which of these types of radiation can pass through the Earth’s atmosphere?
a. microwaves c.gamma rays
b. X rays d. all radio waves
22.Which of these types of radiation cannot pass through the Earth’s atmosphere?
a. microwaves c.gamma rays
b. visible light d.radio waves
Directed Reading B continued
Nonoptical telescopes
Circle the letter of the best answer for each question.
23.What do astronomers use to reveal different clues about an object?
a. different types of radiation
b. different atmospheres
c. visible light
d. colored filters
Radio Telescopes
24.Why do radio telescopes have to be much larger than optical telescopes?
a. They have much shorter wavelengths.
b. They have much longer wavelengths.
c. They use bigger lenses.
d. They collect less light.
Linking Radio Telescopes
25.What do radio telescopes work like when they are linked together?
a. a refracting telescopec.an optical telescope
b. a giant telescope d.an electromagnetic spectrum
26.What is the name of a telescope made up of 27 linked radio telescopes?
a. Very Large Telescopec.Very Large Array
b. Very Linked Array d.Very Limited Array
Nonoptical Telescopes in Space
27.Why have scientists placed X-ray telescopes in space?
a. because Earth’s atmosphere blocks X rays
b. because Earth’s atmosphere blurs X rays
c. to reduce air pollution
d. to avoid light pollution
Section: Mapping the Stars
patterns in the sky
Circle the letter of the best answer for each question.
1.What are constellations?
a. sky regions with star patterns
b. stars
c. star patterns
d. galaxies
2.How did ancient cultures use the constellations’ locations and movements?
a. to measure the universe
b. to build roads
c. to plot out land
d. to navigate and track time
3.What constellation was the same as the Greek constellation Orion?
a. Ursa Major
b. Great Bear
c. Japanese constellation of a drum
d. Japanese constellation of a hunter
Constellations Help Organize the Sky
4.What does each constellation share with a neighboring constellation?
a. star c. border
b. galaxy d. sky
5.How many constellations are there?
a. 18 c. 100
b. 88 d. 288
Directed Reading B continued
Seasonal Changes
Circle the letter of the best answer for each question.
6.When do the apparent locations of constellations seem to change?
a. from year to year
b. twice a year
c. every other year
d. from season to season
7.Why do constellations seem to move with the seasons?
a. Earth tilts on its axis.
b. Earth revolves around the sun.
c. Stars move with the seasons.
d. Stars rotate around Earth.
8.Where do people see constellations different from those in the Northern Hemisphere?
a. Southern Hemisphere
b. Western Hemisphere
c. Texas
d. United States
finding stars in the night sky
Read the description. Then, draw a line from the dot next to each description to the matching word.
9.a tool used to tell a star or planet’s location10.the line where the sky and Earth appear to meet
11.the angle between an object and the horizon
12.an imaginary point right above an observer’s head / •
•
•
• / a.altitude
b.astrolabe
c.horizon
d.zenith
Directed Reading B continued
Read the description. Then, draw a line from the dot next to each description to the matching word.
13.the sun’s location on the first day of spring14.the sun’s apparent path as seen from Earth
15.an imaginary sphere that surrounds Earth
16.an imaginary extension of Earth’s equator into space / •
•
•
• / a.celestial equator
b.celestial sphere
c.ecliptic
d.vernal equinox
17.how far east an object is from the vernal equinox
18.how far north or south an object is from the celestial equator / •
• / a.right ascension
b.declination
Directed Reading B continued
The Path of Stars Across the Sky
Circle the letter of the best answer for each question.
19.What stars never set and can be seen all year long?
a. shooting stars c.northern stars
b. circumpolar stars d.evening stars
the size and scale of the universe
Measuring Distance in Space
20.What is a light-year?
a. the distance light travels in 1 year
b. the speed of light
c. the time it takes light to travel
d. the amount of light in 1 year
21.How many kilometers are in a light-year?
a. 1 c. about 9.46
b. about 1 trillion d.about 9.46 trillion
Considering Scale in the Universe
22.What is an important thing to consider when thinking of the universe?
a. shape c. scale
b. angle d. color
the doppler effect
23.What makes sound seem higher as it moves closer and lower as it moves away?
a. sound effect
b. wavelength effect
c. drowser effect
d. Doppler effect
Directed Reading B continued
Circle the letter of the best answer for each question.
24.When a galaxy moves quickly away from an observer, how does the light appear to change?
a. It looks bluer. c.It looks greener.
b. It looks redder. d.It stays the same.
25.When a galaxy moves quickly toward an observer, how does the light appear to change?
a. It looks bluer. c.It looks greener.
b. It looks redder. d.It stays the same.
26.What effect occurs when a galaxy moves quickly away from an observer?
a. greenshift c. redshift
b. wavelength effect d.blueshift
An Expanding Universe
27.What did Hubble discover about galaxies?
a. They were moving apart.
b. They were moving closer.
c. They didn’t move.
d. They were shrinking.
28.What did Hubble discover about the universe?
a. It’s getting bigger.
b. It’s getting smaller.
c. It’s getting colder.
d. It’s getting redder.
29.How did Hubble discover the universe was getting bigger?
a. by redshift c.by yellowshift
b. by blueshift d.by greenshift
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology1Studying Space