Earth Moves
What motion of Earth causes day and night?
Earth rotating, or spinning, on its axis causes day and night.
Which side of Earth is having daytime?
The side facing the Sun is having daytime.
What creates a shadow?
A shadow forms when an object blocks light.
What object gives Earth its light and heat?
The Sun
What type of display can help show patterns in shadow length?
A graph, chart, table, or line plot.
About how long does Earth take to make one full rotation?
About 24 hours, or one day.
Which side of Earth is having nighttime?
The side turned away from the Sun is having nighttime.
When the Sun appears low in the sky, what usually happens to a shadow?
The shadow is usually longer.
What is the Moon doing as it moves around Earth?
The Moon is orbiting, or revolving around, Earth.
If you measure the same object’s shadow every hour, what should you record?
The time and the shadow’s length. Direction is also helpful.
What is an axis?
An imaginary line that Earth spins around, running between the North and South Poles.
Why do different places on Earth have day and night at different times?
Earth is always rotating, so different places face the Sun at different times.
Around midday, when the Sun is high in the sky, what usually happens to shadows?
They are usually shorter.
What makes the Moon look like it changes shape during the month?
We see different amounts of the Moon’s sunlit side as it orbits Earth.
If a shadow gets shorter from morning to noon, what pattern do you notice?
The Sun appears higher in the sky, and the shadow length decreases.
What is the difference between rotation and revolution?
Rotation is spinning on an axis. Revolution is traveling around another object, like Earth orbiting the Sun.
If St. Louis is facing away from the Sun, what time of day is it likely to be?
It is likely nighttime.
What two shadow details can scientists measure to find patterns?
They can measure shadow length and shadow direction.
Why are some stars visible only during certain seasons?
Earth revolves around the Sun, so we face different parts of space at different times of the year.
Why should scientists collect more than one data point?
Multiple data points make it easier to see patterns and support conclusions with evidence.
Why does the Sun seem to move across the sky during the day?
Earth is rotating, so the Sun appears to change position from our point of view.
Why is it not daytime everywhere on Earth at the same time?
Because Earth is a sphere and only one side faces the Sun at a time while Earth rotates.
Use the words rotation, axis, Sun, and shadow to explain why shadows change during the day.
Earth rotates on its axis. As Earth turns, the Sun appears to move across the sky. That changes the angle of sunlight, so shadows change length and direction during the day.
Name one pattern caused by Earth’s motion in space.
Possible answers: day and night, changing shadows, changing Moon positions, or different stars visible during the year.
A student says, “Shadows change because the Sun goes around Earth.” How would you correct that idea?
The Sun appears to move, but the change happens because Earth rotates on its axis.