A reddish Moon rises behind the Lincoln Memorial. The building is lit up against a dark sky.

Moonrise near the Lincoln Memorial in Washington, D.C. Credit: NASA/Bill Ingalls

Some of our most commonly asked Moon questions, answered.

Q: Does the Moon make its own light (like the Sun does)?

A: No, the Moon reflects the light of the Sun, just as the planets do. The bright part of the Moon is experiencing daytime.

Q: Does the Moon rotate?

A: Yes. The time it takes for the Moon to rotate once around its axis is equal to the time it takes for the Moon to orbit once around Earth. This keeps the same side of the Moon facing towards Earth throughout the month.

If the Moon did not rotate on its axis at all, or if it rotated at any other rate, then we would see different sides of the Moon throughout the month.

Q: Is there a dark side of the Moon?

A: The Moon has no side that is constantly dark. As the Moon rotates, different parts of its surface experience day and night. During a full Moon, it is daytime on the side of the Moon that faces Earth (also called the “near side”). During a new Moon, it is night on the near side, and day on the far side.

Q: Are phases of the Moon caused by shadows from Earth?

A: No. The Moon is always half-lit. The side of the Moon facing the Sun appears bright because of reflected sunlight, and the side of the Moon facing away from the Sun is dark. Our perspective on the half-lit Moon changes as the Moon orbits Earth. When the side nearest to us is fully lit, we call this a full Moon. When the far side is fully lit and the near side is dark, we call this a new Moon. When we see other phases, we are looking at the line between lunar night (the dark part) and day (the bright part).

Occasionally, the Sun, Earth, and Moon align so that Earth's shadow makes the face of the full Moon appear darker and redder than usual. This is called a lunar eclipse.

Q: Can I see the Moon during the day?

A: Yes! The Moon is up just as much during the day as it is at night, but you might not notice it as easily. Because the Sun is also up, and because the Moon phases that are most often visible in daylight show us only a little bit of the Moon’s bright side (like the crescent Moon phases), the Moon is harder to see during the day.

Q: Does the Moon go around Earth every day?

A: It takes about one month for the Moon to orbit Earth (27.3 days to complete a revolution, but 29.5 days to change from New Moon to New Moon).

Q: Can people in different countries see different phases of the Moon on the same day?

A: No, everyone sees the same phases of the Moon. (People north and south of the equator do see the Moon’s current phase from different angles, though. If you traveled to the other hemisphere, the Moon would be in the same phase as it is at home, but it would appear upside down compared to what you're used to!)

Q: Does the Moon have any gravity? Do things float "up" when dropped on the Moon?

A: The Moon does have gravity. Because the Moon has less mass than Earth, its gravitational pull is weaker. On the Moon, you’d be able to jump about six times as high as you can on Earth - but you would still come back down!

Q: Why does the Moon look largest when it is close to the horizon?

A: This is an optical illusion. Prove it for yourself here!

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