Jupiter Opposition, Meteor Showers, Lunar Occultation: A Brilliant Winter Sky Awaits in December!
The winter night sky is filled with bright stars, and this December promises to be especially spectacular. Highlights include Jupiter’s opposition, featuring the highest elevation angle in a decade and optimal viewing conditions, the rare “double shadow transit” of Jupiter's moons, the year's final Geminid meteor shower, and Mercury reaching its greatest western elongation alongside a lunar occultation of a first-magnitude bright star. It's a feast for stargazers! Jupiter reaches opposition on December 8 (Sunday), marking its brightest and best viewing period. With a magnitude of -2.8, it becomes the night sky’s brightest object and remains visible all night. Jupiter's four famous moons can be observed with simple binoculars, while an astronomical telescope reveals features such as its banding and the Great Red Spot. When the shadows of Jupiter's four largest moons are cast onto its surface, a rare phenomenon known as a " shadow transit" will occur. At 19:00 on December 30 (Monday), Io and Ganymede will simultaneously cast shadows, creating the extraordinary "double shadow transit." This event is truly worth observing. December 14 (Saturday) marks the peak of the spectacular Geminid meteor shower. The estimated hourly zenith meteor rate (ZHR) is about 150. However, due to the influence of moonlight that night, the number of meteors visible will be significantly reduced. Nevertheless, the Geminid meteor shower is known for its fast meteors and frequent bright bolides, so if the weather is clear, there is still a chance to spot many bright ones! This year’s winter solstice falls on December 21 (Saturday), when the sun shines directly on the Tropic of Capricorn, and the northern hemisphere will experience the shortest day and longest night of the year. Although the winter solstice is not the day when the sun rises the latest or sets the earliest, the sunrise and sunset directions on that day are the most southerly in the whole year. You might as well observe this interesting phenomenon.A "lunar occultation of Spica" will occur in the early morning of December 25 (Wednesday). At 2:07, the first-magnitude bright star Spica will be obscured from the bright edge of the moon and temporarily disappear. At 3:08, it will suddenly reappear from the moon's dark edge. It is recommended to use binoculars to observe or record the complete process of the occultation with photography. In the early morning of the same day, there will be the last "Western Elongation of Mercury" this year, which is also a good opportunity to observe Mercury. From 5:30 to before dawn, as long as you search at a low altitude in the southeast and east, it is not difficult to find this sparkling but rarely observed planet. For detailed information, please refer to the Taipei Astronomical Museum website.