The phases of the moon are periodic and repetitive. A new moon occurs when no moon is visible to an observer on Earth. During the first quarter, half of the side of the moon facing the Earth is visible. During a full moon the entire
side of the moon is visible. During the last quarter the other half of the side of the moon facing Earth is visible.
The U. S. Naval Observatory lists the following dates for phases of the Moon in the year 2008.
Date Moon Phase x: Days since y: The Amount of
Jan. 8
Moon Visible
Jan 8 New
JO
10
Jan 15 1st quarter
7
0.5
Jan 22 Full
13
1
Jan 30 Last quarter 22
10.5
Feb 7 New
30
0
Feb 14 1st quarter 37
10.5
Feb 21 Full
44
1
Feb 29 Last quarter 52
10.5
Mar 7 New
59
o
Mar 14 (1st quarter
66
0.5