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The Question
(Submitted April 08, 1997)
What sequence of events in the solar system is responsible
for completing one month on our calendar?
The Answer
The month is roughly based on the time from full Moon to full Moon
as seen from the Earth. This is between 29 and 30 days.
Now there are two catches:
1. There are not an even number of "Moons": in one year nor an even
number of days in a "Moon," so we have a calendar that only approximates this
by dividing up the year into 12 months.
2. The actual time it takes for the Moon to orbit the Earth is only about
than 27 days, however because the Earth orbits the sun the Moon has to go
a little farther before we see it as full again. Therefore, there are about
12 "Moons" in a year, but the Moon goes around the Earth about 13 times
Thanks for asking.
Sincerely,
Jonathan Keohane
-- for Imagine the Universe!
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