Landing Site Coordinates

The locations of the Apollo landing spots relative to local landmarks are very accurately known. Details can be found in the Apollo Landing Sites Slide Set compiled by James R. Zimbelman.

The longitude and latitude values associated with those points depend on our evolving understanding of the shape of the Moon and have been subject to revision. In the following table, the LM coordinates listed in the second and third columns have been adapted from a table in Zimbelman's paper. These values agree with those given in the various Mission Reports issued shortly after each flight. The values in the fourth and fifth columns come from a 1987 paper by Davies et al as listed on the National Space Science and Data Center webpage.

With regard to the 1987 values, "Site coordinates are based on the IAU Mean Earth Polar Axis coordinate system, from the transformed Defense Mapping Agency 603 (DMA/603) lunar cartographic control network as described in Davies et al., J. Geophys. Res., v. 92, pp. 14177-14184, 1987 and personal communication (1998). The Apollo 11, 12, and 14 landing site locations are estimated from the transformed DMA/603 network and the relative locations of the ALSEP's (Apollo Lunar Surface Experiments Packages) and LRRR's (lunar ranging retroreflectors) as given in the Apollo ALSEP Termination Report and Apollo Preliminary Science Reports."

The two sets differ. Bob Craddock of the Smithsonian Institution's National Air and Space Museum comments, "The location of lunar landing sites and other significant features described in the Davies and Colvin paper are based on Apollo retroreflectors data integrated for individual locations and translated into geographic coordinates using Apollo and Lunar Orbiter data. The numerical values of the derived coordinates have uncertainties related to the uncertainties of the retroreflector data integrations and the resolution of the available photographic information. In addition, the numerical values depend heavily on which coordinate system you're using (that is, how you describe the shape of the moon) as well as which data you use to derive a solution (that is, determining where the landing site is in 3-d space). It is not any easy thing to do at all. Differing results come from different models with different solutions. Currently, the lunar geoid is being redefined with Clementine data, so the location (latitude, longitude, and elevation) of everything will change again very soon."

In short, we know where each of the LMs is located is relation to local landmarks; but assignment of latitude and longitudes to those locations is an evolving process.