How much aperture does it take?
Seeing The Moon through a telescope
Blinding, grey-white, and far more three-dimensional than photographs suggest. The best detail is never at full Moon — it is along the terminator, where the shadows are long.
Through three telescopes, under a suburban sky
Each circle is the true field of a 25 mm eyepiece. Same target, same sky; only the aperture changes.
Detailed
Detailed
Detailed
The aperture it takes, by sky
The Moon does not care about light pollution: it is bright, and the air, not the sky glow, sets the limit.
| Level | Milky Way blazing | Milky Way, barely | No Milky Way |
|---|---|---|---|
| Detectable | 1 mm | 1 mm | 1 mm |
| Recognisable | 1 mm | 1 mm | 1 mm |
| Detailed | 60 mm | 60 mm | 60 mm |
What more aperture buys
A 60 mm shows more craters than you can count in an evening. Aperture past about 150 mm mostly buys resolution the atmosphere will not deliver.
When to look
Any clear night in the ten days around first quarter.