Researchers were baffled as to why the moon’s surface warmed slightly in measurements over the course of six years from 1971.
Astronauts on the Apollo 15 and Apollo 17 moon missions in 1971 and 1972 respectively had measured the temperature with probes to explore whether the core was hot like Earth.
These devices sent data back to NASA headquarters in Houston, USA, but the only records to be archived were between 1971 and 1974 – but 1975 to 1977 logs were missing.
Now researchers have found the lost records and discovered that the answer was a man made problem.
Studying images of the moon’s surface they found that missions had disturbed the ground where the space craft landed.
And this made the lunar soil darker which meant it absorbed more heat from the sun, reported RT.
The darkening caused the moon to increase in heat by up to two degrees.
“It doesn’t take much disturbance to get that very subtle warming on the surface,” scientist Seiichi Nagihara, the study’s lead author at Texas Tech University, said.
“In the process of installing the instruments you may actually end up disturbing the surface thermal environment of the place where you want to make some measurements.
”That kind of consideration certainly goes in to the designing of the next generation of instruments that will be someday deployed on the moon.”
The findings were published in the Journal of Geophysical Research.