Question

Felipe believes that whenever the Moon is in the position that is shown from above (top view) in Diagram A, the Moon always looks completely bright in the view from Earth, as shown in Diagram B. Is Felipe correct? If he is correct, explain why the Moon always looks bright from Earth in that position, and explain how he should show light on the Moon in Diagram A. If he is incorrect, explain how else the Moon can look when it is in that position.

Answer 1

Answer: Felipe is wrong.

Explanation:

In diagram A, we can see that the light comes from the left, it first impacts on the Earth, and then we have the Moon.

Now, you can model this situation with a flashlight (the Sun) a basketball (the Earth) and a tennis ball (the Moon)

When you point with the flashlight at the basketball, the basketball will look bright, but it will cast a shadow behind it. This shadow will cover the tennis ball, and almost no light will reach the tennis ball, so it will not look bright.

This phenomenon is called a lunar eclipse, and this happens when the Earth is in between the Sun and the Moon. When this happens, we see the moon a bit darker and more reddish.