The moon moves about 2.5 centimeters away from our planet every year, so that in a few hundred million years, there will be no more solar eclipses, say scientists from NASA.
The measurements were made with lasers and panels called retro-reflectors, set up by US and Russian missions over the past few decades. The findings are published in the journal Earth, Planets and Space.
The concept of measurement is how long the laser sent from Earth travels to the Moon, bounced off the retro-reflector. NASA’s Erwan Mazarico is in charge of the project, which has been running since 2017 in the southern French city of Grasse, and he claims that, although not always, it succeeds.
On the other hand, Tom Murphy, a physicist from the University of California, who is not involved in the project, says that time, age, and external influences damage the panels and that, most likely, affects the effectiveness of measurements. “The explanation with the dusty spotlights is much more acceptable than rejected, given the results,” he said.
However, he and some of his colleagues agree that this knowledge is important for building the whole picture.
Mazarico, on the other hand, believes that there is not enough evidence that the excessive layer of moon dust sticking to the retro-reflectors is the “categorical culprit” for the slowness of the process.