This could be fodder for moon landing deniers – the Eagle may not have landed a second time. Wait … what? For those who don’t get the reference, on July 20, 1969, Commander Neil Armstrong radioed the following message from the lunar surface: “Houston, Tranquility base here. The Eagle has landed.” That meant the Apollo 11 Lunar Module nicknamed ‘Eagle’ descended successfully. On July 21, Armstrong and Aldrin left the surface of the moon with their cargo of 22 kilograms of lunar rock in the ascent stage of Eagle. After docking and unloading, the Eagle was undocked and it was assumed to have ended a retrograde orbit by plummeting back to the surface for a second, albeit un-eagle-like, landing. Unfortunately, it was not tracked and no one knows where it crashed. Or did it?
Space enthusiast and Eagle researcher James Meador is not affiliated with NASA, but perhaps he should be. He tells Discover magazine he became intrigued with what happened to the Eagle after hearing about NASA’s 2012 mission to map the Moon’s gravitational field using a pair of spacecraft called GRAIL (Gravity Recovery and Interior Laboratory). They showed that the Moon’s mass is not evenly distributed, which causes tiny variations in its gravitational field that make most lunar orbits unstable in the long term.
In 2012, NASA sent a pair of spacecraft called GRAIL to map the Moon’s gravitational field and this mission eventually created a detailed map of this varying field. Meador decided to use the data to calculate where the Eagle’s impact crater debris might be. This was not an issue with the lunar ascent modules from Apollos 12, 14, 15, 16 and 17 because surface seismometers left by the astronauts recorded their impacts. GRAIL data is available to the public, as is an open-source program called the General Mission Analysis Tool developed by NASA and others to model a spacecraft’s trajectory in any gravitational field.
“The simulations show a periodic variation in eccentricity of the orbit, correlated to the selenographic longitude of the apsidal line. The rate of apsidal precession is correlated to eccentricity. These two factors appear to interact to stabilize the orbit over the long term.”
The model takes into account outside forces such as the gravitational pull of the Earth, the Sun and all the planets except Mercury and calculates how a spacecraft’s orbit changes over time. Meador used the supplied set of starting parameters for the Eagle — the time of jettison, the latitude, longitude and altitude, heading angle and others, and was able to manipulate them to see if they produced different results. Instead, they all came to the same conclusion. (Meador details the research in a pre-print paper.)
“Numerical analysis described here provides evidence that this object might have remained in lunar orbit to the present day.”
In other words, the Eagle HASN’T landed – it may still be in orbit. That means it could be located and observed. The Indian Space Research Organization lost contact with the Chandrayaan-1 lunar orbiter, less than half the size of Eagle, in 2009 and it was found again in 2016 by modeling where it should be and aiming radar at that spot. In 2019, NASA found Apollo 10’s lunar module named Snoopy which had been left behind by the crew during their test flight for Apollo 11. That one left lunar orbit and was found circling the Sun.
So, finding the Eagle is entirely possible. Will it convince deniers that the Moon landing really happened? Probably not. Will Jeff Bezos offer to retrieve the Eagle and bring it back to Earth so Buzz Aldrin can see it? Only if NASA gives him an exclusive contract.
The post Part of Apollo 11’s ‘The Eagle Has Landed’ Spacecraft May Still Be in Orbit Around the Moon first appeared on Mysterious Universe.