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[Centaur]

EDIT: The answers are given in the next post.

How well do you know the Moon? Don't be afraid to provide your answers/guesses. The first one to answer all five questions correctly will be designated Lunatic for the Night.

1) What is the average number of days between successive Full Moons?
-- A. 27.32
-- B. 28.10
-- C. 29.53
-- D. 30.44
-- E. 31.76

2) On average the Moon rises how many minutes later each day?
-- A. 11.91
-- B. 19.28
-- C. 31.19
-- D. 50.47
-- E. 81.67

3) What phase is the Moon if it rises about sunset and sets about sunrise?
-- A. Dark of the Moon (New Moon)
-- B. Waxing Half Moon (First Quarter)
-- C. Full Moon
-- D. Waning Half Moon (Last Quarter)
-- E. It could be any phase.

4) The phases of the Moon recur on approximately the same dates after what number of years?
-- A. 4
-- B. 7
-- C. 10
-- D. 14
-- E. 19

5) Over the long run (586-year cycle), what percentage of Full Moons are totally eclipsed?
-- A. 0.7%
-- B. 1.4%
-- C. 2.8%
-- D. 5.6%
-- E. 11.2%

[Centaur]

My fellow Chicagoans shame me. I thought we were supposed to be the bold ones - the smart ones. But no one here had the courage to take the test. They did so at other sites where I presented the same quiz. Two had perfect scores and became Lunatics for the Night. Oh my.

Here are the correct answers to the quiz with some comments.

1) What is the average number of days between successive Full Moons?
-- C. 29.53

A synodic month can actually vary between 29.28 and 29.83 days due principally to the Moon’s variable speed along its eccentric orbit.

2) On average the Moon rises how many minutes later each day?

-- D. 50.47

Divide 1440 (minutes in a day) by 28.53 to get the answer. The latter figure is the average number of times the Moon rises during a synodic month. It is one less than 29.53 because the Moon laps the Sun every synodic month.

3) What phase is the Moon if it rises about sunset and sets about sunrise?
-- C. Full Moon

The Full Moon is on the opposite side of the sky from the Sun.

4) The phases of the Moon recur on approximately the same dates after what number of years?
-- E. 19

This is the famous Metonic cycle mentioned by the Greek astronomer Meton around 430 BC. 235 synodic months very nearly equal 19 tropical years.

5) Over the long run (586-year cycle), what percentage of Full Moons are totally eclipsed?
-- D. 5.6%

This figure varies quite a bit from century to century. From 1650 through 1749 it was 4.8%. From 1950 through 2049 it is 7.0%. So we’re living during a relatively rich period for total lunar eclipses.

[Chicago Astronomer - Astro Joe]

I seemed to have overlooked this post...D'oh!

Numbers four and five would have been unknown to me.

Oh boy...

[Centaur]

Chicago said:

Numbers four and five would have been unknown to me.

They're known now. It was not expected that all would be known; it was supposed to be a learning experience. Apprently there was some success in that regard. Actually, if one knew the answer to #1 and the average number of days in a year, he could have tested the candidate answers to #4 and deduced the correct choice. Ditto regarding #1 and #2 - only one pair of answers was consistent. ;D