Rotation
This is how long it takes Earth to rotate once.
24 hours
This is how long it takes Earth to orbit the sun.
365.25 days
What determines the length of a shadow?
sun’s position in the sky
This model puts Earth at the center.
geocentric model
True or False: Earth’s orbit causes day and night.
false
This causes day and night on Earth.
Earth’s rotation
Earth’s orbit causes this pattern in the night sky.
different constellations during the year
Shadows are longest at this time of day.
when the sun is low (morning or late afternoon/early evening)
This model puts the sun at the center
heliocentric model
What causes shadows to change during the day?
sun’s position in the sky
How many times does Earth rotate in one year?
365.25 times
Why do we have leap years?
Earth’s orbit is 365.25 days - so when we add up the 0.25 days it adds up to one day every four years giving us 366 days in a year every four years
This tool uses shadows to tell time.
sundial
What is stellar parallax?
when nearby stars appear to shift or move slightly in the sky during the year because Earth is orbiting the Sun.
True or False: All constellations are visible every night.
false
Name one piece of evidence that Earth rotates
This happens at the same time as Earth’s orbit.
Earth’s rotation
Why do we have 24 time zones?
Earth rotates and different places experience daylight at different times
This observation proved the geocentric model wrong.
stellar parallax
This instrument gives physical evidence Earth rotates.
Foucault pendulum
Explain why the sun appears to move across the sky even though it is not actually moving.
Earth is rotating on its axis, which makes it look like the sun is moving across the sky.
Explain why we see different constellations at different times of the year.
As Earth orbits the sun, our view of space changes, so we see different constellations in different months.
A student notices their shadow is very short at noon but very long in the afternoon. Explain why this happens.
The sun is higher in the sky at noon, making shadows short. As Earth rotates, the sun appears lower in the sky, making shadows longer.
Explain why scientists changed from the geocentric model to the heliocentric model.
geocentric model - Earth is at the center, and everything in space moves around Earth. This model is not correct.
Heliocentric model - The Sun is at the center, and the planets, including Earth, orbit around the Sun. This model is correct.
Observations like stellar parallax showed that stars change position as Earth orbits the sun, proving Earth is not the center.
List TWO observations that show Earth rotates on its axis and explain ONE of them.