Dating of microcraters formed on the lunar surface

It has been observed that the latent damage trails produced by charged particles in glassy spherules from lunar samples are annealed due to the impact of micrometeorites. The impacts are found to 'reset' the clock monitoring the time period elapsed since the cooling down of the glassy spherules. A study of the geometry and the track densities produced 'just below' the molten surface and those lying 'deep inside' the body of the micrometeorites yields useful information concerning the time period elapsed since the impact took place and the ages of solidification. The technique so developed has been used to study the 'impact histories' of microcraters produced on glassy spherules obtained from Apollo-15 lunar samples. (author)