Prepare to Read

Learn Key Vocabulary

Rating Scale

  • 1 = I have never seen this word before.

  • 2 = I am not sure of the word’s meaning.

  • 3 = I know this word and can teach the word’s meaning to someone else.

Rate and Study the Words Rate how well you know each word. Then:

  • 1. Pronounce the word. Say it aloud several times. Spell it.

  • 2. Study the example.

  • 3. Tell more about the word.

  • 4. Practice it. Make the word your own.

Key Words
distance (dis-tunts) noun page 457
Photograph of woman looking up toward the sun
Distance is the area between two points. The distance between Earth and the sun is 93 million miles.		orbit (or-but) verb page 461
Illustration of planets with dashed rings to show the path of their orbits
To orbit means to move in an almost circular path around another object. It takes Earth about 365 days to orbit the sun.		space (spās) noun page 456
Photograph of a spaceship in orbit around Earth
Space is the area beyond Earth. Scientists send special ships into space to learn about other planets and the moon.
telescope (te-lu-skōp) noun page 459
Photograph of person standing next to a telescope
A telescope is a tool you can look through to make faraway things look bigger.You can use a telescope to look at the moon.		temperature (tem-pur-chur) noun page 460
Photograph of a thermometer with snow around it
The temperature is how hot or cold something is. We measure temperature using a thermometer.		unit (yū-nit) noun page 458
Photograph of an object being measured with an inch rulerA unit is a certain amount used in measuring.An inch is a common unit used to measure small objects.
universe(yū-nu-vurs) noun page 456
Illustration of a spiral galaxy
The universe is everywhere and includes Earth, all other planets, and all stars.		vary (vair ē) verb page 460
Photograph of snowflakes
To vary means to be different from others. Snowflakes vary from one another so that no two are alike.		Practice the Words Make a Word Map for each Key Word. Then compare your maps with a partner’s.
Word Map

Word Map