Apollo 12 Mission
Landing Site Overview
The Apollo 12 lunar module made a precision landing on the lunar surface on November 19, 1969, in Oceanus Procellarum at 3°11'51" south latitude and 23°23'8" west longitude. The touchdown point was on the northwest rim of Surveyor Crater only 600 feet from the target point, the Surveyor III spacecraft, which landed on April 20, 1967. This precision landing was of great significance to the future exploration program because landing points in rough terrain of great scientific interest could then be targeted.
"At first glance out of the spacecraft window, there was absolutely no distinguishable color difference. About the only difference noticed was in looking cross-Sun versus looking down-Sun. There were no immediately apparent white rim craters near us. Most of the craters observed from the LM window did not have any particular elongation. The craters seemed to be the same texture as the area surrounding them. All the material looked the same until we were very close to the individual rocks."
Landing Site Selection
As with Apollo 11, engineering and safety considerations dominated the criteria for landing site selection for Apollo 12:
Smoothness: Relatively few craters and boulders
Approach: No large hills, high cliffs, or deep craters that could cause incorrect altitude signals to the lunar module landing radar
Propellant Requirements: The least expenditure of spacecraft propellants
Recycle: Effective launch preparation recycling if the Apollo Saturn V countdown is delayed
Free Return: Within reach of the spacecraft launched on a free-return translunar trajectory
Slope: Less than 2° slope in the approach path and landing site
These criteria dictated landing in a mare region near the equator. Mare regions in Oceanus Procellarum were given high priority because telescopic study suggested that these areas are younger and of a slightly different composition than the Apollo 11 landing site.
Because Apollo 11 landed about 4 miles beyond its planned target, it was deemed important to demonstrate a precision landing capability on Apollo 12. This capability was vital to the success of later, more complex missions. Accordingly, a landing at the Surveyor 3 landing site was planned. This provided both a clear marker for determining the accuracy of the landing as well as an opportunity to return pieces of the spacecraft to Earth to determine the effects of 2 1/2 years in the lunar environment. Also, this landing site offered the possibility of sampling ejecta from the large crater Copernicus, thereby constraining the age of this crater. Finally, this landing site allowed good orbital imaging of the Fra Mauro site that was later explored by Apollo 14.
Stereoscopic Views of the Landing Site
Red/Green (Anaglyph) Images
To view anaglyph stereo pairs you need red-green (or red-blue) stereo glasses. These glasses have a red lens over the left eye and green (or blue) lens over the right eye.
Black and White Images
To view side-by-side stereo pairs, use pocket stereo viewers (obtainable from local educational suppliers, bookstores, etc.).
Side-by-side stereo pairs can also be viewed with the unaided eye by focusing on each image separately and allowing the eyes to cross. If you wear glasses, it may be necessary to remove them and view the pairs from 6 to 10 inches away. These techniques may require some practice (the Apollo 15, 16 and 17 stereo pairs are good for this purpose). Another means of assisting this process is to place an index card upright between the two images, forcing each eye to see the different images. Only approximately 10% of the general public cannot view images stereoscopically.
The Apollo 12 landing site is located on the smooth volcanic plains of Oceanus Procellarum. The landing site is marked by a small green cross. Like Apollo 11, this site was chosen for its lack of relief, as comparison with subsequent landing sites shows. The bright streak running vertically across the scene is a bright ray of ejecta from the large crater Copernicus located over 300 kilometers to the north. These views (Hasselblad frames AS12-54-8090 and AS12-54-8091) show an area 29 kilometers across from top to bottom, with north at the top. The vertical exaggeration is about 3.
|Surface Views of the Landing Site|
|Panoramic Views Around the Landing Site|
North from the Apollo 12 Landing Site
|East from the Apollo 12 Landing Site|
|South from the Apollo 12 Landing Site|
|West from the Apollo 12 Landing Site|