Tuesday, May 06, 2008

Chasing a very, very, young crescent moon

Session name: 20080505.1830

This crescent moon had all the makings for a record. A personal record and one that would rank in an area where few have succeeded. A 12 hour crescent moon set in the west with best of all conditions - except the weather.

The Moon is an Aries.
The angle of the ecliptic by Aries is nearly vertical to the horizon when setting.
The Moon is north of the ecliptic, increasing the angle to the horizon and situauting the Moon more vertical to the Sun.
Elongation was 8°32'E with illumination at 0.6%.
Exceeds Danjon's Limit of 7° or 7°30'.
Moon's age at sunset was 11h37m; age at the the time of predicted sighting 11h58m when the Sun was a little more than 4° below the horizon and the Moon at an altitude a little greater than 3°.

File a report or get details at crescentmoonwatch.org. I submitted one indicating crescent not seen.
If the weather agrees we can observe a 36 hour crescent Moon this evening. Still a splendid, magical sight of our sister world that laps the Sun with us. If you have binoculars or a telescope watch sunrise beginning in Mare Crisium and Mare Anguis.

A Method for Predicting the First Sighting of the New Crescent Moon (Yallop)
Calculating the length of crescent moon (cusp to cusp) (Sultan)
First Visibility: Beyond Danjon's Limit (Sultan)

Search for H. R. Blackwell

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