Earth's Rotation & Revolution
How long does Earth take to rotate once on its axis?
24 HOURS / 1 DAY
What causes the seasons on Earth?
The tilt of Earth’s axis (23.5°
How long does it take the Moon to orbit Earth?
About 28.5 days
What type of eclipse happens when the Moon blocks sunlight from reaching Earth?
Solar eclipse
What causes tides on Earth?
The Moon’s gravitational pull (and the Sun’s, to a lesser degree)
How long does it take for Earth to complete one revolution around the Sun?
365 days / 1 YEAR
When is the Northern Hemisphere tilted most toward the Sun?
Summer Solstice (around June 21)
What causes moon phases?
The Moon’s position relative to Earth and the Sun
What eclipse happens when Earth’s shadow falls on the Moon?
Lunar eclipse
How many high tides occur each day?
TWO
What shape is Earth’s orbit around the Sun?
An ellipse
When are day and night equal everywhere on Earth?
Equinox (spring/fall)
What phase occurs when the Moon is completely lit from Earth’s view?
Full Moon
During which Moon phase does a solar eclipse occur?
New Moon
What tides occur during full and new moons?
Spring tides
Which way does Earth rotate?
Counterclockwise (west → east)
Which hemisphere experiences winter when the Northern Hemisphere has summer?
Southern Hemisphere
What is it called when the Moon is more than half lit but not full?
Gibbous Moon
During which Moon phase does a lunar eclipse occur?
Full Moon
What tides occur during quarter moons?
Neap tides
What is the difference between rotation and revolution?
Rotation = spin on axis; Revolution = orbit around the Sun
Why are seasons reversed between hemispheres?
Because of Earth’s tilt, each hemisphere tilts toward/away from the Sun at different times of year
Why do we always see the same side of the Moon?
Because the Moon rotates once per orbit TIDAL LOCKING
Why don’t eclipses happen every month?
Because the Moon’s orbit is tilted compared to Earth’s orbit around the Sun
Why are high tides on both sides of Earth at once?
Gravity pulls water on the near side, and inertia causes bulging on the far side