Search for supernova debris on the Moon

The enhanced deposition of ⁶⁰Fe in a deep ocean ferro-manganese crust about (2.1±0.4) Myr ago indicate that one or more supernova (SN) explosions occurred in the vicinity of the Solar System. That observation was only possible with the ultrasensitive Accelerator Mass Spectrometry (AMS) technique at the Maier-Leibnitz-Laboratory, which is able to measure concentrations of ⁶⁰Fe/Fe down to a level of 10^-16 and even below. Due to its lack of atmosphere and its negligible sedimentation rate, the Lunar surface is an excellent quantitative reservoir for SN debris. We searched for live ⁶⁰Fe (T_1/2 = 2.62 x 10⁶ yr) and ⁵³Mn (T_1/2 = 3.7 x 10⁶ yr) in different samples from 3 Apollo missions. ⁵³Mn is, similar as ²⁶Al and ⁶⁰Fe, a tool to trace nucleosynthesis activities. It is formed primarily during the explosive silicon-burning of the inner shells of SNe via ⁵³Fe which β-decays to ⁵³Mn. Samples where we found an enhanced ⁶⁰Fe concentration showed also an enhancement of ⁵³Mn. This could be the first detection of live ⁵³Mn originating from recent nucleosynthesis.