I am looking for dates in history, from 400 years ago or older, when there was an occultation of Venus by the Moon during Winter as seen from Sicily. Venus was rising, and according to the text that I am trying to fact check, it is not clear what phase the moon is in. The text from Shakespeare reads there were "nine changes to the watery star" This is interpreted to mean the moon, as it effects the tides. So the moon should be 9 days away from a full moon.

Or if an occultation is too rare would there be an appulse that matches the criteria?

1) Venus is rising. 2) The moon is waning nine days. 3) As seen from Sicily.

I am led to understand that this is a rare event, happening once every 200 years or more, and I would be curious to know about any other unusual astronomical events that occurred within +/- 23 or 24 years of this rare event.

Where could I find this information? Is there a star chart I could check?

  • 1
    $\begingroup$ Did you mean occultation? $\endgroup$
    – Mike G
    Commented Jun 3, 2020 at 10:47
  • $\begingroup$ It could be an occultation. How often does that occur? $\endgroup$ Commented Jun 3, 2020 at 15:31
  • 3
    $\begingroup$ Lunar occultations of planets are fairly rare and observable from a limited area. $\endgroup$
    – Mike G
    Commented Jun 3, 2020 at 16:31
  • 2
    $\begingroup$ There is a module in stellarium that lets you compute astronomical events in a given interval of time. $\endgroup$
    – usernumber
    Commented Jun 4, 2020 at 8:06

1 Answer 1


If the Moon is 9 days past full, then it can't be occulting (or even at its closest approach to) Venus. Since Venus is an interior planet, it never gets far from the Sun in the sky as seen from Earth; its maximum elongation (maximum angle between Sun and Venus) is 47°. So to occult Venus, the Moon would also have to be that close to the Sun in the sky.

However, when the Moon is 9 days past full, it is still more than 70° from the Sun in the sky (verified with calculation of lunar position and phase from JPL Horizons; the "SOT" angle given there is "Sun-Observer-Target" and thus the Sun-Moon angle as seen from Earth). The Moon doesn't get within 47° of the Sun until about 11 days past full.

On a more literary note, the passage "nine changes of the watery star" (from The Winter's Tale) seems to be typically interpreted in commentaries to mean nine months have passed, i.e. each "change" is a full cycle of lunar phases.

EDIT: If you want to search for historical occultations in general, it looks like the Windows software Occult 4 should be able to do it. The PDF guide has some tips for setting it up.


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