Question

1. what causes the moon’s phases?

a. the rotation of the moon on its axis
b. earth’s tilt on its axis as it revolves around the sun
c. the motion of the moon and the sunlight reflected from its surface
d. the position of the moon each month in relation to the north star

1. the cycle of the moon through its phases, or the synodic month, is

a. 21 days long.
b. 27 1/3 days long.
c. 29 1/2 days long.
d. 30 days long.

1. a solar eclipse occurs when

a. earth casts a dark shadow on the moon.
b. the moon casts a dark shadow on earth.
c. earth casts a dark shadow on the sun.
d. the sun casts a dark shadow on the moon.

Explanation:

1. The moon's phases are caused by its position relative to the Earth and Sun, and the sunlight reflected from its surface. As the moon orbits Earth, different portions of its sun - lit side are visible from Earth.
2. The synodic month, which is the cycle of the moon through its phases, is approximately 29.5 days long. This is because it takes the moon about 29.5 days to return to the same position relative to the Earth - Sun system.
3. A solar eclipse occurs when the moon comes between the Earth and the Sun, casting a dark shadow on Earth.

Answer:

1. c. the motion of the moon and the sunlight reflected from its surface
2. c. 29 1/2 days long
3. b. the moon casts a dark shadow on Earth