Glossary
Rising and Setting
- Order of rising & setting of Moon
-
Since the Sun rises in the morning and sets in the evening, sunset always follows sunrise. But because the Moon moves eastward, moonrise and moonset gets late day by day.
- Since the Moon is near the Sun around New Moon, the Moon rises in the morning and sets in the evening.
- Around 1st Quarter, the Moon rise around noon and sets around midnight.
- Since the Moon is in the opposite direction of the Sun, the Moon rises in the evening and sets in the following morning.
- Around Last Quarter, the Moon rises around midnight and sets around following noon.
So around Full Moon, for example, the Moon sets in the morning and reappears in the evening (Moonrise occurs after moonset!).
| | Date | Rise | Azi. | Set | Azi. |
|---|
| Phase | Y/M/D | H:M | deg. | Time | deg. |
|---|
| New Moon | 2006/09/22 | 5:00 | 85.7 | 17:29 | 270.6 |
|---|
| 1st Quarter | 2006/09/30 | 12:55 | 126.5 | 22:09 | 233.9 |
|---|
| Full Moon | 2006/10/07 | 17:15 | 79.9 | 5:24 | 275.7 |
|---|
| Last Quarter | 2006/10/14 | 22:55 | 59.0 | 13:12 | 302.6 |
|---|
- Days with no moonrise or moonset
-
As we explained in Order of rising & setting of Moon, the times of moonrise & moonset gets late day by day and eventually passes midnight. Let's look at moon rise and moonset on 2006/10/15, for example.
- The Moon rises at 23:58 on 10/15 and sets at 14:21 on the next day (10/16).
- The Moon should rise later like 24:xx.
- But 24:xx on 10/16 is equal to 0:xx on 10/17, specifically, 0:58 on 10/17.
- So, we do not have moonrise on 10/16.
In Koyomi Station, days with no moonrise, transit or moonset are expressed as --:--.
| Date | Rise | Azi. | Set | Azi. |
|---|
| Y/M/D | H:M | deg. | H:M | deg. |
|---|
| 2006/10/15 | 23:58 | 63.8 | 13:50 | 298.3 |
| 2006/10/16 | --:-- | ----- | 14:21 | 292.9 |
| 2006/10/17 | 0:58 | 69.8 | 14:48 | 286.7 |
- Days with rising / setting / transit happens twice
-
When you are at higher latitude, or in the case of outer planets, rising / setting / transit can happen twice a day.
Rising and setting of Saturn around 2008/12/04
| Date | Rise
HH:MM | Azi.
deg. | Set
HH:MM | Azi.
deg. |
|---|
| 2008/12/04 | 0:02
23:58 | 83.0
83.1 | 12:36 | 277.0 |
| 2008/12/05 | 23:54 | 83.1 | 12:32 | 276.9 |
- Saturn rises at 0:02 on 12/4 and sets at 12:36 same day.
- Since Saturn rises around every 23 hour and 56 minutes, it rises again on 23:58 on 12/04 and sets at 12:32 on 12/5. That means Saturn rises twice on 12/4.
- And Saturn rises again at 23:54 on 12/5.
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