The Apollo 11 Eagle Lunar Module ascent stage was abandoned in lunar orbit after the historic landing in 1969. Its fate is unknown.
Numerical analysis described here provides evidence that this object might have remained in lunar orbit to the present day.

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.

Long-term Orbit Stability of the Apollo 11 Eagle Lunar Module Ascent Stage
James Meador

Comments: 13 pages, 8 figures. Submitted to Planetary and Space Science
Subjects: Space Physics (physics.space-ph)
Cite as: arXiv:2105.10088 [physics.space-ph] (or arXiv:2105.10088v1 [physics.space-ph] for this version)
Submission history
From: James Meador
[v1] Fri, 21 May 2021 01:52:20 UTC (2,620 KB)
https://arxiv.org/abs/2105.10088