Earth, Moon, and Sun

Text Vocabulary (pg. 2-5) – “Where Is Earth in Space?”

Vocabulary
Terms / Text
Page / Vocabulary
Definition
lithosphere / 2 / Earth’s rigid outer layer
hydrosphere / 2 / All of Earth’s water
atmosphere / 2 / Layer of gases surrounding a planet
meteoroid / 3 / Space rock smaller than an asteroid
planet / 3 / Large sphere in space that revolves around a star and does not produce its own light
orbit / 3 / Path an object takes when revolving around another object
Sun / 3 / Name for the star at the center of our solar system
moon / 3 / Natural satellite that revolves around a planet
satellite / 3 / Object that revolves around another object
solar system / 3 / A star and the planets, moons, and other objects that revolve around it
asteroid / 3 / Rocky space object that revolves around the Sun, mostly in a region between Mars and Jupiter
comet / 3 / Chunk of ice, rock, and frozen gases
star / 4 / Enormous sphere of glowing gases that gives off heat and light
light-year / 4 / Distance that light can travel in one year
galaxy / 4 / System of stars, dust, and gases held together by gravity
universe / 4 / All of space, including all of the matter and energy within it
gravity / 5 / Universal force that attracts, or pulls, all objects that have mass toward one another
law of universal gravitation / 5 / Gravity exists between any two objects with mass, and the strength of gravity depends on the mass of the objects and the distance between them
weight / 5 / Measurement of the pull of gravity on an object

Earth, Moon, and Sun

Text Vocabulary (pg. 6-7) – “What Is the Sun Like?”

Vocabulary
Terms / Text
Page / Vocabulary
Definition
solar energy / 6 / Energy from the sun
corona / 6 / Outer layer of the Sun’s atmosphere
solar wind / 6 / Charged particles that escape from the Sun’s corona and travel through space
chromosphere / 6 / Part of the Sun’s atmosphere that is above the photosphere
photosphere / 6 / Lowest layer of the Sun’s atmosphere that gives off light
prominence / 6 / Huge loop of glowing gas that extends out from the Sun
core / 6 / Center part of the Sun that is the source of the Sun’s energy
nuclear fusion / 6 / Reaction in the Sun when four hydrogen atoms fuse together, or combine, to form helium, producing large amounts of energy
radiation zone / 7 / Area of the Sun where energy is transferred by electromagnetic waves
convection zone / 7 / Area of the Sun where energy is transferred by flowing gases
telescope / 7 / Instrument used to study distant objects; it creates larger images of distant objects
sunspot / 7 / Cooler regions in the Sun’s photosphere
electromagnetic spectrum / 7 / All of the types of electromagnetic radiation
solar flare / 7 / Intense bursts of energy on the Sun that occur when built-up electromagnetic energy is released
spectrometer / 7 / Instrument that splits a star’s visible light into a band of colors, used to determine a star’s composition

Earth, Moon, and Sun

Text Vocabulary (pg. 8-10) – “What Causes Days and Years?”

Vocabulary
Terms / Text
Page / Vocabulary
Definition
axis / 8 / Imaginary line that runs from a planet’s north pole to its south pole on which the planet rotates
rotation / 8 / Act of turning or spinning on an axis
day / 8 / Length of time it takes for a planet to rotate once on its axis
time zone / 9 / One of the 24 standard zones into which Earth is divided, corresponding to the 24 hours in a day
International Date Line / 9 / Imaginary line passing through the western Pacific Ocean that marks the start of a new day
revolution / 10 / Act of moving in a curved path or orbit around another object
year / 10 / Length of time it takes for a planet to make one complete revolution around the Sun
ellipse / 10 / An elongated circle; oval

Earth, Moon, and Sun

Text Vocabulary (pg. 11-12) – “What Causes Seasons?”

Vocabulary
Terms / Text
Page / Vocabulary
Definition
season / 11 / Periodic change in climate caused by the change in solar energy due to the axial tilt of Earth as Earth orbits the Sun
axial tilt / 11 / Angle at which a planet’s axis tilts
latitude / 12 / Distance north or south of the equator, expressed in degrees
solstice / 12 / Two times of year when the Sun’s direct rays strike Earth the farthest north or south of the equator
equinox / 12 / When the Sun’s rays directly strike the equator and both hemispheres have 12 hours of daylight and 12 hours of darkness

Earth, Moon, and Sun

Text Vocabulary (pg. 13-15) – “What Is the Moon Like?”

Vocabulary
Terms / Text
Page / Vocabulary
Definition
maria / 13 / Smooth, flat plains on the Moon that appear as dark patches
highlands / 13 / Hilly areas of the Moon that appear as light patches
crater / 14 / Depression on the surface of a planet or moon caused by a meteorite impact
phases / 15 / Changes in the appearance of the Moon as it orbits Earth
waxing / 15 / Growing larger in appearance
waning / 15 / Growing smaller in appearance

Earth, Moon, and Sun

Text Vocabulary (pg. 16-17) – “What Causes Tides?”

Vocabulary
Terms / Text
Page / Vocabulary
Definition
tide / 16 / Regular rise and fall of the ocean’s surface
tidal range / 16 / Difference between the level of the ocean at high tide and at low tide
spring tides / 17 / High tides that are higher than normal and low tides that are lower than normal due to the Sun and Moon lining up with Earth
neap tides / 17 / High tides that are lower than normal and low tides that are higher than normal due to the Sun and Moon being at a right angle to Earth

Earth, Moon, and Sun

Text Vocabulary (pg. 18-19) – “What Causes Eclipses?”

Vocabulary
Terms / Text
Page / Vocabulary
Definition
eclipse / 18 / When one object in space moves into the shadow cast by another object
lunar eclipse / 18 / When the Moon moves into Earth’s shadow
umbra / 18 / Darkest part of the shadow cast by Earth or the Moon during an eclipse
penumbra / 18 / Lighter part of the shadow cast by Earth or the Moon during an eclipse
solar eclipse / 19 / When Earth moves into the Moon’s shadow