Students have submitted lots of questions about the Moon. Click on each question to see its answer. Do you have a Moon question that isn’t already answered here? Submit it using the form at the bottom of this page.
- and Breccias
- Apollo 11: Buzz Aldren and Neil Armstrong (July 1969)
- Apollo 12: Alan Bean and Charles Conrad (November 1969)
- Apollo 14: Edgar Mitchell and Alan Shepard (January 1971)
- Apollo 15: James Irwin and David Scott (July 1971)
- Apollo 16: Charles Duke and John Young (April 1972)
- Apollo 17: Harrison Schmitt and Eugene Cernan (December 1972)
- The waxing crescent rises shortly after sunrise and follows the Sun across the sky. Because it is so close to the Sun, we can't see it until after the sun sets. It is only visible for a short time before it dips below the horizon.
- The 1st Quarter moon rises in the late morning or early afternoon. You can see this phase of the moon in the afternoon and evening.
- The Waxing Gibbous moon rises in the late afternoon just before the sun sets and can be seen until a few hours before sunrise.
- The Full Moon rises when the Sun sets. It is visible all night long. It sets in the morning when the Sun rises.
- The Waning Gibbous moon rises later in the evening and can be seen until the early morning hours just following sunrise.
- The Third Quarter moon rises after midnight and can be seen till just before noon.
- The Waning Crescent rises a few hours before sunrise and can be seen until a few hours before the sun sets.
- The New moon rises and sets with the Sun. For about two to three days we will not be able to see the moon in the day or the night.
People began naming the features of the Moon around 1609, when Galileo first looked through his home-made telescope. It is a very human action to look at something strange and try to see familiar things in it. That has led many people to look at the Moon and imagine they can see a face in it. In the photo above, the features that create that effect have been highlighted to make them show up more clearly. These features are not really a face, of course ... they are geological formations that just happen to look like a face. Here is a list of some of geology features on the Moon:
- Mare = lava plain
- Mons = mountains
- Montes = mountain range
- Palus = dark plain
- Rima = crack, rille
- Rupes = cliff
- Sinus = bay
- Vallis = valley
Our Moon spins on its axis so that as it orbits the Earth, it always presents the same face to the Earth. As a result, when viewed from the Moon, the Earth will always remain in about the same spot in the sky all the time! (This may be easier to see if you set up two balls (using a light as the Sun) and make a model of the situation; place yourself on the Moon ball and you'll see what the Earth then looks like at any point in your orbit.)
I say that it is about the same because there are some differences. For example, there are slightly different apparent sizes of the Earth due to the fact that the orbit of the Moon is not a perfect circle; sometimes the Earth is closer (and appears larger) and sometimes it is farther away (and appears smaller) in each orbit. Also, because the orbit of the Moon is tilted about 5 degrees with respect to the Earth's equator, from the Moon there will be locations where the Earth will slowly rise and set during the lunar month as seen from the surface. The Moon undergoes a motion called "libration" which causes it to rock slightly back and forth relative to a line connecting the centers of the Earth and the Moon. This libration effect, as seen from the Moon, will cause the Earth to move slightly back and forth in the sky relative to a fixed point above the lunar horizon.
It is also important to note that the Earth will go through a complete set of phases each lunar month, with a "Full Earth" happening when it is "New Moon", and a "New Earth" happening during "Full Moon" (in other words, they will appear to be in exactly opposite phases).
In summary, while it generally remains in the same location, the Earth does not remain perfectly stationary in the lunar sky from every point on the Moon, but moves in a rather complicated way depending on your location on the lunar sphere!
(This information courtesy of Nasa.gov's Starchild page.)
All surfaces of the Moon are exposed to the Sun at some point during a month. During the sunlit days on the far side of the Moon you could see the surface of the Moon very well and, since the Moon has no atmosphere, you could also see the Sun and stars in a black sky. The trick to seeing the stars, though, would be to shield your eyes from all reflections and glare off the surface (and, of course, from the bright light of the Sun). Without blocking off all this extra light, the light from the stars would be overwhelmed by the glare and our eyes are not sufficiently sensitive to be able to see the much, much fainter light from the stars.
However, when the Moon is full, its far side is turned completely away from the sun, so during a full moon, the far side of the Moon really would be dark. On those days, the surface of the Moon would be extremely hard to see, but the stars would appear very much brighter than they do from here on Earth.
The colors of sunrise and sunset would also be very different on the Moon. On Earth, the sun's light is scattered by our atmosphere, which gives us the colors of sunrise and sunset, and causes the gradual lightening at sunrise and darkening at sunset. The atmosphere is also what makes Earth's sky look blue during the day. The Moon has no atmosphere, so there would be no colors. The Sun would appear as a plain bright white dot in a black sky. The surface of the Moon would suddenly be lighted at the moment the Sun becomes visible, and would plunge back into darkness at the moment it sinks out of sight -- there would be no gradual dawn or dusk.
This "false color image" taken by the Galileo orbiter uses added colors to show geological features of the Moon. Blue to orange shades indicate volcanic lava flows. The band of gray along the right side of the image shows you what the Moon actually looks like without any special color enhancements. By NASA/JPL - http://photojournal.jpl.nasa.gov/catalog/PIA00131