Astronomical Information | 2016 | December
The sky of Tokyo
Calendar (December)
| 7 | First Quarter Moon |
| 10 | Saturn at conjunction |
| 11 | Greatest Eastern Elongation of Mercury |
| 14 | Full Moon/ Geminid Meteor Shower peaks around 9:00 (The best time to observe is after midnight on the morning of the 14th. On the order of 10 meteors per hour are expected. Because the Moon is very bright, conditions are bad.) |
| 19 | Mercury at stationary point |
| 21 | Last Quarter Moon/ Winter solstice (Sun’s ecliptic longitude 270°) |
| 23 | Emperor’s Birthday [Tennou-Tanjyobi] (national holiday) |
| 29 | New Moon/ Mercury at inferior conjunction |
| 30 | Uranus at stationary point |
The days for the peak activities of the meteor showers are based on the predictions of IMO (International Meteor Organization).
Planets
- Mercury
- Mercury is positioned low in the southwestern sky after sunset. It reaches greatest eastern elongation on the 11th, but at 30 minutes after sunset its elevation is less than 10 degrees, making observations difficult. On the 29th Mercury reaches inferior conjunction.
- Venus
- Venus can be seen low in the southwestern sky after sunset. Its elevation increases rapidly at the end of the month. Its brightness is -4.1 magnitude to -4.3 magnitude.
- Mars
- Mars can be seen in the southwestern evening sky moving from the constellation Capricorn to the constellation Aquarius. Its brightness is 0.6 magnitude to 0.9 magnitude.
- Jupiter
- Located in the constellation Virgo, Jupiter can be seen in the southeastern to southern sky before dawn. Its brightness is -1.8 magnitude to -1.9 magnitude.
- Saturn
- Saturn’s apparent location is close to the Sun, making it unsuited for observation. Saturn reaches conjunction on the 10th.
Source: Ephemeris Computation Office, NAOJ
With the “Sky Viewer” you can easily explore the appearance of a typical urban night sky (planets and constellations are visible).The Celestial Phenomena section of the glossary explains the planetary phenomena terms: greatest elongation, opposition, conjunction, stationary, etc.