A shadow of the Moon, with a statistical significance of 5 sigma, has been
observed in the underground muon Aux at a depth of 2090 mwe using the Souda
n 2 detector, The angular resolution of the detector is well described by a
Gaussian with a sigma less than or equal to 0.3 degrees. The position of t
he shadow confirms that the alignment of the detector is known to better th
an 0.15 degrees and has remained stable during ten years of data taking.