A table listing some of the Astronomical Phenomena for December 2017:
Phenomena December
| Day (UT) | Time (UT) | Event |
|---|---|---|
| 3 | 07:49 | Mercury (mag. 0.2) begins retrograde motion. |
| 3 | 13:25 | Moon 0.8 degrees north of Aldebaran (mag. 0.9), occultation visible from northeast Asia, Alaska, northwest Canada. |
| 3 | 15:48 | Full moon. |
| 4 | 08:52 | Moon is at perigee, approx. 357,495 kilometres or 222,137 miles from the Earth. |
| 6 | 12:31 | Moon 8.7 degrees south of Pollux (mag. +1.1). |
| 7 | 23:46 | Vesta (mag. 7.9) 4.4 degrees north of Jupiter (mag. -1.7). |
| 8 | 17:16 | Venus (mag. -3.9) 5.1 degrees north of Antares (mag. 1.0). |
| 8 | 22:51 | Moon 0.7 degrees north of Regulus (mag. +1.4), occultation visible from northern Europe, northern Asia. |
| 10 | 07:52 | Last quarter moon. |
| 12 | 11:48 | Mercury is at perihelion 0.307 AU (approx. 45.9 million kilometres or 28.5 million miles) from the Sun. |
| 12 | 21:26 | Moon 7.2 degrees north of Spica (mag. +1.0). |
| 13 | 02:59 | Mercury is at inferior conjunction. |
| 13 | 16:28 | Mars (mag. 1.6) 4.2 degrees south of Moon. |
| 14 | 06:00 | Geminids meteor shower peaks (ZHR = 120) |
| 14 | 14:26 | Jupiter (mag. -1.7) 4.2 degrees south of Moon. |
| 14 | 18:35 | Vesta (mag. 7.9) 0.2 degrees north of Moon. |
| 16 | 18:17 | Moon 9.4 degrees north of Antares (mag. 1.0). |
| 18 | 06:31 | New moon. |
| 19 | 01:43 | Moon is at apogee, approx. 406,604 kilometres or 252,652 miles from the Earth. |
| 21 | 16:29 | Winter Solstice NH - Summer Solstice SH. |
| 21 | 20:06 | Ceres (mag. 7.8) begins retrograde motion. |
| 21 | 21:10 | Saturn is in conjunction with the Sun . |
| 22 | 15:00 | Ursids meteor shower peaks (ZHR = 10 - occasionally up to 50) |
| 23 | 02:42 | Mercury (mag. 0.3) begins direct motion. |
| 24 | 12:40 | Neptune (mag. 7.9) 1.4 degrees north of Moon. |
| 26 | 09:21 | First quarter moon. |
| 27 | 18:02 | Uranus (mag. 5.8) 4.5 degrees north of Moon. |
| 31 | 00:50 | Moon 0.8 degrees north of Aldebaran (mag. 0.9). |