Question

Astronomy ranking task phase of the moon

Astronomy Ranking Task: Phases of the Moon Exercise #2 Description: The figure below shows a "top view" of the Sun, Earth and six different positions (A - F) of the Moon during one orbit around Earth. Note that the distances shown for the Sun to Earth and for Earth to the Moon are not drawn to scale Orbit of Moon OD Sunlight SUN NOT TO SCALE Ranking Instructions: Rank (from greatest to least) the amount of the Moon's illuminated surface that is visible from Earth at each of the six positions (A - F) shown. Ranking Order: Greatest 1 2 Or, the amount of the Moon's illuminated surface visible from Earth is the same in all positions 4 Least (indicate with check mark) Carefully explain your reasoning for ranking this way:

Answer 1

A full moon appears in the sky, when all of the illuminated surface is visible. Since this has to happen at night, the bright side of the moon should entirely face the earth. This is position A. Similarly, for a new moon to occur, the dark side of the moon should entirely face the earth. This is position D. For intermediate positions, the closer the moon is to position A, the more will its surface be lit. If it is equidistant from A and D, half of the moon surface will be lit. Thus, from greatest to least, the rank of is

A, F, E and B, C, D.

E and B both appear to be half illuminated from the Earth's surface nad thus should have the same rank.