Earth-Sun-Moon System Patterns Flashcards

A model shows Earth, the Sun, and Moon with the Moon between Earth and the Sun but slightly above the orbital plane. What event does this represent?

Answer: A new moon with no eclipse

Because the Moon's orbit is tilted about 5 degrees relative to Earth's orbital plane, most new moons pass above or below the Sun-Earth line without causing an eclipse.

Which statement best explains why the Southern Hemisphere experiences summer in December?

Answer: The Southern Hemisphere tilts toward the Sun during December

When the Northern Hemisphere tilts away from the Sun in December, the Southern Hemisphere tilts toward it, receiving more direct sunlight and experiencing summer.

An observer on Earth watches the Moon over four weeks. On day one it is not visible (new moon). On about which day would a full moon appear?

Answer: Day 14–15

The Moon reaches the full phase approximately 14–15 days after a new moon, when it has moved halfway through its orbit.

Why does the Sun appear to move across the sky from east to west each day?

Answer: Earth rotates from west to east, making the Sun appear to move westward

Earth rotates eastward on its axis, which makes the Sun and other celestial objects appear to move westward across the sky.

If Earth had no axial tilt, which of the following would be true?

Answer: There would be no seasons; all locations would have consistent day length year-round

Without axial tilt, Earth's equator would always face the Sun equally, eliminating seasonal changes in temperature and day length.

A student records moonrise times for a month and notices the Moon rises about 50 minutes later each successive night. What best explains this pattern?

Answer: The Moon orbits Earth eastward, so it appears slightly farther east each night and Earth must rotate more to bring it into view

As the Moon moves eastward in its orbit, Earth must rotate an extra ~50 minutes to 'catch up' to the Moon's new position, delaying moonrise.

Which of the following is a pattern that repeats approximately every 18 years and involves eclipses?

Answer: The Saros cycle

The Saros cycle is approximately 18 years and 11 days long, after which the Sun, Earth, and Moon return to nearly the same relative positions, repeating eclipse patterns.