Mascons

While these results provide a better picture of the Venus crust, what is most compelling about the analysis, which James presented on March 1 at the Lunar and Planetary Science Conference, is the discovery that there are no large mass concentrations, or "mascons," buried beneath the surface of Venus. ❋ Unknown (2010)

“I was very interested in additional information about the mascons based on the Apollo 10 experience,” relates Armstrong. ❋ James R. Hansen (2005)

The fact that Apollo 10, flying the same orbit that we were going to be flying, was documenting the influence of the mass concentrations on our own exact trajectory was very important to us, because mascons could affect how well we would be able to get to our desired landing point. ❋ James R. Hansen (2005)

“I was very interested in additional information about the mascons” Ibid. ❋ James R. Hansen (2005)

Howard W. Tindall Jr., Apollo Data Priority Coordination, to a long list of individuals at the MSC, “Subject: How we will handle the effects of mascons on the LM lunar surface gravity alignments,” July 14, 1969, NASA Manned Spacecraft Center, copy in Historical Archives, University of Houston—Clear Lake. ❋ James R. Hansen (2005)

* Even after Apollo 10, some of the Apollo mission planners were still concerned about the effects of mascons. ❋ James R. Hansen (2005)

There was also the matter of the lunar environment itself, especially the possibly significant gravitational effects that mascons might have on the flight paths of the Apollo 11 spacecraft. ❋ James R. Hansen (2005)

Perturbations likely caused by mascons had led to slight dips in the paths of the Lunar Orbiters. ❋ James R. Hansen (2005)