The Moon Guide
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U. S. N. O.
The phase of the Moon right now


How much can you see?

Numbered map of Moon
Features to look for with the naked eye
< Seas and mountains

Seen through a telescope or binoculars, the Moon appears to be mass of seas, craters and mountains. How can you learn your way around? Fortunately, you can make a start just by observing with your own eyes, and in doing so you will be one stpe ahead when it comes to observing through a telescope.

You can test your own naked-eye visual acuity with the following list of objects, compiled by the American astronomer W H Pickering. Starting with the easiest, and becoming progressively more difficult, they are:

  1. Bright region around Copernicus
  2. Mare Nectaris
  3. Mare Humorum
  4. Bright region around Kepler
  5. Gassendi region
  6. Plinius region
  7. Mare Vaporum
  8. Lubiniezky region
  9. Sinus Medii
  10. Faintly shaded area near Sacrobosco
  11. Dark spot at foot of Mt Huyghens
  12. Riphean Mountains

Those with good eyesight will be able to discern Mare Vaporum with little trouble. Last on the list, the Riphean Mountains represent a challenge for those with superb eyesight because the light grey cluster of peaks is only around 2 arcminutes across.

Irregularities along the Moon’s terminator (the line dividing the day side of the Moon from its night side) can sometimes be seen with the naked eye.
Sinus Iridum
Sinus Iridum: just visible
The most noticeable of terminator irregularities becomes apparent when Sinus Iridum has just emerged into the morning sunshine (Moon around 10 days old) and the brilliant curve of the bordering Jura mountains projects into the darkness beyond. The big craters Ptolemaeus and Clavius also make dents on the terminator each fortnight, though better than average eyesight is needed to see them.

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Crescent Moon

Observing the Moon

Moon lighting

'Seas' and mountains

How much can you see?

Using binoculars and telescopes

Drawing the Moon

Getting to know the Moon

Three-day crescent Moon

Six-day crescent Moon

First-quarter Moon

Gibbous Moon

Interactive Moon map

spacerMaintained by SPA Webmaster: Last modified 23 November 2008
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