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This is a picture of the lunar farside taken on 12/24/1968. The picture was taken from the Apollo 8 spacecraft.
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Courtesy of NASA

What are the flat surfaces on the Moon called? What is maria? What are lunar highlands?

What phase was the Moon in on December, 22 1962? How long does it take the Moon to travel from one phase to the next?

Suppose that the Moon spun twice on its axis during each orbit around the Earth. How would study of the Moon from the Earth be easier?

If the Moon is tilted only slightly with respect to the Sun, do the lunar poles receive nearly constant sunlight?

Wow! More Moon questions! Okay, here goes... There are only two types of regions on the Moon's surface. Dark regions on the Moon are called maria. They are smooth, flat plains with few craters. The light-colored highlands are hilly and are covered with craters.

The U.S. Navy has created a web page where you can find the moon phase for any day in years 1800-2199. Check it out! The time between 2 new moons is 29.5 days. Say there are 8 phases of the Moon, New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full, Waning Gibbous, Last Quarter and Waning Crescent. So that's 3.69 days from one phase to the next.

We can only see half of the Moon from Earth. The Moon is locked into a specific orbit around the Earth so that we only see one side. If the Moon spun twice during each orbit around the Earth, it wouldn't be locked into that orbit and we could see the far side of the Moon from Earth. As it is now, we can only see the far side of the Moon when a spacecraft takes a look for us.

Since the Moon is tilted only a tiny bit, the poles do receive NEARLY constant sunlight. You can think of the Moon having two sides at any given time, the side facing the Sun and the side facing away from the Sun. If you stand anywhere on the side facing the Sun (from the poles to the equator), you'll be in NEARLY direct sunlight (unless you're in a crater or behind a hill!). And on the side facing away, it'll be really dark!

Submitted by Nicholas (Rhode Island, U.S.A.), Megan, Vilma (Texas, U.S.A.), Craig (North Carolina, U.S.A.), Margaret (Oklahoma, U.S.A.), Vicky (New York, U.S.A.), Joni (West Virginia, U.S.A.)
(January 12, 2001)
Last modified January 10, 2001 by Jennifer Bergman.

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF