During the Surveyor V landing, a footpad with an attached permanent magnet assembly slid for about a meter through lunar surface material at a depth of about 10 centimeters. Subsequent pictures showed material adhering to the magnetic pole edges, where the magnetic field strength is greatest. Comparison of these pictures with those made under simulated laboratory conditions permits three conclusions. (i) Iron is present on the lunar surface in one of the forms attracted to a 500-gauss magnet. (ii) A 1-percent addition by volume of powdered free iron to a powdered terrestrial rock represents an upper limit for the lunar results. (iii) The lunar results are most similar to a terrestrial plateau basalt with no addition of free iron.
A magnet assembly consisting of a magnetized bar and an unmagnetized bar was attached to a footpad of Surveyor 6 in such a manner that it would permit viewing by the television camera following the lunar landing of the spacecraft and after the assembly had made contact with the lunar surface. Results of the experiment indicate that there is a small amount of magnetic material present in the Sinus Medii and appear to support a basaltic composition. This experiment strengthens the conclusion that basaltic composition may dominate the maria units, and the basalt may be scoriaceous. In addition, the magnet experiments lend support to a volcanic origin of this mare material, and would further suggest fine particles at the time of origin, rather than subsequent pulverization by impact.
A permanent magnet and nonmagnetic control bar attached to a footpad of Surveyor 5 represent the first magnetic experiment on lunar mare material. This magnet assembly revealed the presence of magnetic material in Mare Tranquillitatis, the Surveyor 5 landing site. Television pictures showed relatively small amount of magnetic material adhering to the magnet. All particles appeared to be smaller than camera resolution. The pictures have been compared in detail with various laboratory simulations of impact in powdered rock types with and without additions of powdered iron. The closest laboratory analogy was found in powdered basalt (37 to 50 μ) with no addition of powdered iron.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.