Earth, Moon, and Sun
Text Read to Understand Questions (pg. 2-5) – “Where Is Earth in Space?”
Text Question
What function does Earth’s
atmosphere serve?
What is a satellite, and how
do satellites stay in orbit?
Why would your weight be
different on another planet?
Answer
The function of the Earth’s atmosphere is to:
 keep the temperature even
 block dangerous rays from the Sun
 contains gases needed for life
 cause meteoroids to burn
A satellite is an object that orbits another
object in space. The force of gravity and a
satellite’s high speed keep it in orbit.
Your weight would be different on another
planet because different planets have
different masses so the force of gravity
pulling down is different.
Earth, Moon, and Sun
Text Read to Understand Questions (pg. 6-7) – “What Is the Sun Like?”
Text Question
How does energy from the
Sun’s core travel into space?
What are some ways that
scientists study the Sun and
other stars?
Answer
Energy from the core travels outward by
electromagnetic waves. It is carried by hot,
convecting gases to the Sun’s surface.
Energy from the Sun’s surface travels out into
space as light. Some energy is also released
in solar flares.
Scientists use telescopes, infrared and x-ray
technologies, and spectrometers to study the
Sun and other starts.
Earth, Moon, and Sun
Text Read to Understand Questions (pg. 8-10) – “What Causes Days and
Years?”
Text Question
How is Earth’s rotation
related to day and night?
How is time related to your
location on Earth?
Why is the length of a year
different for each planet?
Answer
The time it takes for Earth to complete one
rotation is a day. At any point in Earth’s
rotation, the side of Earth facing the Sun
experiences day, and the side facing away
from the Sun, night.
Earth is divided into 24 time zones, each 1
hour apart.
The time it takes each planet to complete
one revolution around the Sun is different.
The planets that are closer to the Sun have
smaller orbits and revolve faster.
Earth, Moon, and Sun
Text Read to Understand Questions (pg. 11-12) – “What Causes Seasons?”
Text Question
Answer
Earth’s tilt causes the poles to point toward
How is Earth’s axial tilt related or away from the Sun at different times of
to the seasons?
the year, causing the amount of solar energy
received by the different hemispheres to
change over the course of a year.
The hemisphere experiencing summer gets
Why is summer in the
more direct solar energy and the days are
Northern Hemisphere warmer longer, making temperatures warmer.
than winter?
How are solstices and
equinoxes related to the
position of Earth in its orbit?
Solstices occur during Earth’s orbit when the
Sun’s direct rays strike farthest north or
south of the equator. Equinoxes occur when
the Sun’s rays strike the equator directly.
Earth, Moon, and Sun
Text Read to Understand Questions (pg. 13-15) – “What Is the Moon Like?”
Text Question
Answer
How do meteorites shape the Bowl-shaped depressions called craters form
Moon’s surface?
when meteorites hit the Moon.
The same side of the Moon always faces
Why does the same side of Earth because it takes the same amount of
the Moon always face Earth? time for the Moon to complete one
revolution around Earth as it does to
complete one rotation on its axis.
What causes the phases of
the Moon?
Like all bodies in the solar system, half of the
Moon is always lit by the Sun. As the Moon
orbits Earth, we see a different amount of
the lighted half. The lighted portion visible
from Earth changes shape a little each day.
Earth, Moon, and Sun
Text Read to Understand Questions (pg. 16-17) – “What Causes Tides?”
Text Question
How are ocean tides related
to gravity?
Answer
Tides are partly caused by the Moon’s
gravity. Since gravity is stronger when
objects are closer, the Moon’s gravity pulls
harder on the parts of Each closest to the
Moon. This causes a high tide on the side
toward the Moon.
A spring tide is when high tides are higher
What is a spring tide, and how than normal and low tides are lower than
is it caused?
normal. This happens when the Sun is lined
up with the Moon and Earth. The gravity of
the Sun and the Moon pull in the same
direction.
A neap tide is when high tides are lower than
What is a neap tide, and how normal and low tides are higher than normal.
is it caused?
This happens when the Sun is at a right angle
to the Moon and Earth. The gravity of the
Sun pulls water away from the tidal bulges.
Earth, Moon, and Sun
Text Read to Understand Questions (pg. 18-19) – “What Causes Eclipses?”
Text Question
Answer
When can a lunar eclipse be
seen on Earth?
A lunar eclipse can be seen only during a new
Moon when the Moon is between Earth and
the Sun.
When can a solar eclipse be
seen on Earth?
A solar eclipse can be seen only during a new
Moon when the Moon is between Earth and
the Sun.
How can the Moon block our The Moon is 400 times smaller than the Sun,
view of the Sun, which is
but it is also 400 times closer to Earth than
much larger?
the Sun. This makes the Sun and Moon look
a about the same size to us.