Moon Phases
What do we call the phase when the Moon’s lit side faces away from Earth?
New Moon
What do we call it when the Moon passes directly between Earth and the Sun?
Solar eclipse
What causes tides on Earth?
The Moon’s and Sun’s gravitational pull
What evidence did sailors notice that suggested Earth was curved?
Ships disappear hull-first over the horizon as they sail away.
What do we call Earth’s spinning motion on its axis?
Rotation
In which direction does the Moon orbit Earth (when viewed from above the North Pole)?
Counterclockwise.
What type of eclipse occurs when Earth blocks sunlight from reaching the Moon?
Lunar eclipse
What do we call the highest water levels during a day?
high tide
Who measured Earth’s circumference using shadows at different cities?
Eratosthenes
What do we call one complete orbit of Earth around the Sun?
A year or revolution.
What phase comes directly after the first quarter?
Waxing gibbous
Why do solar eclipses happen so rarely?
Because the Moon’s orbit is tilted relative to Earth’s orbit, so the Sun, Earth, and Moon only line up occasionally.
Why are there two high tides each day?
Earth rotates through two tidal bulges caused by the Moon’s gravity.
What is one modern observation that proves Earth is round without needing space photos?
Airplane flight paths and satellite orbits curve along Earth’s shape.
What is the imaginary line around which Earth rotates?
the Earth's axis.
About how long does it take the Moon to complete one revolution around Earth?
27.3 days
What is the imaginary flat plane that Earth orbits on called?
The Ecliptic
How long is the time between one high tide and the next?
About every 12 hours and 25 minutes
What natural phenomenon can be used to show the curvature of Earth’s shadow?
During a lunar eclipse, Earth’s round shadow is cast on the Moon.
How is Earth’s axis tilted relative to its orbit?
23.5 degrees.
What causes the Moon to appear to change shape (e.g. have different phases) throughout the month?
The changing angles of sunlight hitting the Moon as it orbits Earth.
During which Moon phase does a solar eclipse occur?
New Moon
Why is there a tidal bulge both on the side of Earth facing the Moon and on the opposite side?
The Moon’s gravity pulls more strongly on the near side, while the far side lags behind due to inertia, creating two bulges.
How could you prove Earth is round using only stars?
Different constellations are visible from different latitudes- for example, the North Star disappears as you move south.
What would happen to day and night if Earth stopped rotating?
One side constant daylight, one side constant night.