The dark patches of soil uncovered by the Apollo astronauts are clearly visible in overhead photographs. Finding the lost Apollo tapes
Astronauts first planted temperature probes on the moon's surface during the Apollo 15 and 17 missions, in 1971 and 1972. While these probes transmitted data steadily back to the NASA Johnson Space Center in Houston until 1977, only the first three years of recordings were ever archived with the National Space Science Data Center.
For their new study, Kiefer, Nagihara and their colleagues embarked on a quest to find the missing tapes. The researchers tracked down 440 of these tapes at the Washington National Records Center in Suitland, Maryland; unfortunately, that trove of data represented only about three months of temperature records taken in 1975.
To augment the newly recovered records, the team pulled hundreds of weekly performance logs from the Lunar and Planetary Institute. The logs included temperature readings taken from the Apollo probes between 1973 and 1977, meaning the researchers could fill in some of the gaps left by the other missing tapes.
The 12 astronauts who walked on the moon between 1969 and 1972 left enough footprints to change the surface environment. Climate change on the moon
After several years of extracting and analyzing data from the archaic tape reels, the researchers discovered that probes planted near the moon's surface recorded a greater and faster temperature jump than the probes planted deeper down found. This indicated that the temperature spike was beginning at the surface and not within the moon itself, the researchers said.
A quick study of lunar surface photos taken by the Lunar Reconnaissance Orbiter Camera provided another crucial clue. The photos showed that areas near the Apollo landing sites were crisscrossed with dark streaks where the astronauts had walked or driven about the moon's surface, apparently kicking a lot of ancient dust aside.