Read time in the rims.
Measure the crater diameter with the caliper. Record the reliable craters, choose a diameter cutoff at or above the image’s completeness limit, then report the surface age. Aim for counting uncertainty ≤34% and an age within 15% of the synthetic survey’s reference.
Survey specimens
Magnified cutouts from one mapped surface. Each view has its own scale; smaller incomplete craters need not be counted.
Select a specimen. Match the gold caliper endpoints to the outer rim.
The counting notebook
- Recorded craters
- Above cutoff
- Counting uncertainty
- Inferred age
Why not count everything? Below the completeness limit, small craters are missing from the image. Raising the cutoff too far leaves too few counts. The Neukum chronology converts count density to age; uncertainty shown is 1/√N, not a full geological age interval.
Scientific source & assumptions
Chronology and cumulative diameter production functions are scalar ports of Craterstats by Greg Michael (BSD-3-Clause), pinned0879f9fa, using its Moon Neukum2001 coefficients. Synthetic specimens are quantiles of that production function above the completeness limit; a few small visible craters represent an incomplete sample. They are cutouts, not a spatially scaled mosaic. The generated regolith texture underlies every measured specimen. No geological interpretation beyond the stated educational model.