I’m hoping to sneak this in because it involves some clever digital archaeology on 40yo NASA data tapes.
In short, thermometers placed in the moon to record core temperature indicated an abnormal rise in temperature. The authors conclude that this was a local rise due to the astronauts sifting the soil and changing the albedo, causing the moon to absorb more sunlight in those patches.
“In the early years of the ALSEP operation, NASA was preserving the tapes recorded at the downlink stations of the Manned Space Flight Network for archival purpose. These tapes were called “range tapes.” In April 1973, JSC started generating data tapes specifically for archiving, and they were called “ARCSAV tapes” (Lockheed Electronics Company, 1975). The ARCSAV tapes were 7-track, digital, open-reel tapes, and each contained a day’s worth of raw data as received from each of the Apollo stations. JSC generated five ARCSAV tapes for the five ALSEP stations every day from April 1973 to February 1976. In March 1976, University of Texas at Galveston took over the work of generating archival tapes. The tapes made by University of Texas at Galveston were called “work tapes.” They were 9-track digital tapes, and data from all the five ALSEP stations were meshed together in them (Nakamura, 1992).
The range tapes and the ARCSAV tapes were never sent to NSSDC for unknown reason. Most of these tapes were lost in the years following the conclusion of the Apollo program. In year 2010, the present authors recovered 440 ARCSAV tapes at the Washington National Records Center (Nagihara et al., 2011). These tapes contained data from April through June 1975 for all of the 5 ALSEP stations. This accounts for less than 10% of the ARCSAV tapes that were generated during the Apollo era. The rest of the ARCSAV tapes are still missing. Digital copies of the work tapes survived in their entirety, and they have been recently archived at the National Space Science Data Coordinated Archive (NSSDCA), the successor to NSSDC.
Even though the 440 ARCSAV tapes recovered from the Washington National Records Center are more than 40 years old and degraded, we were able to recover most of their contents by trying multiple data-recovery service providers. Some of the files extracted from the tapes included a number of bit errors. Fortunately, because the report describing the bit-level data organization for these tapes survived (Lockheed Electronics Company, 1975), we were able to correct many of these errors (Nagihara et al., 2017).
The recording on the ARCSAV tapes and work tapes consisted of data from multiple experiments intermeshed. Using the bit-level data organizations for these archival tapes described previously, we extracted the HFE packets from the data recorded on the tapes. For the HFE, data packets on the archival tapes consisted of digital counts representative of the voltage outputs from the Wheatstone bridges and the thermocouples. They needed to be processed into scientifically meaningful temperature values. The reports outlining the data processing procedure for the HFE have also survived (Langseth, 1977; Lauderdale & Eichelman, 1974). However, they lack information on the instrument calibration.
Because the RTDs of the heat flow probes needed absolute accuracy of ~0.05 K (Langseth et al., 1972b), each probe unit was calibrated by the companies that designed and fabricated them. The calibration data were not included in any of the reports or research articles previously published by the original investigators. The present authors conducted a search.”