December 4 – New Moon
The Moon will appear on the same side as the Sun when viewed from Earth and will not be present in the night sky. This New Moon phase occurs at 7:44 a.m. UTC. This is the best time of the month to observe faint objects such as galaxies or star clusters without the obstruction of moonlight.
December 4 – Total Solar Eclipse
A total solar eclipse occurs when the Moon completely obscures the Sun, leaving only a beautiful halo of light around it, called a corona when viewed from Earth. The location where this total solar eclipse can be observed is limited to the Antarctic and South Atlantic regions. However, even South Africa can experience a partial eclipse. (according to NASA map and eclipse information)
Vietnam is completely incapable of observing this phenomenon.
December 13 and 14 – Gemini meteor shower (Geminids)
The Geminids meteor shower is considered one of the largest meteor showers of the year. The number at its peak can reach 120 meteors/hour with many large and bright meteors. The origin of the Geminid meteor shower is from the remains of fragments of the asteroid 3200 Phaethon, discovered in 1982. It usually takes place from December 7 to 17 each year, this year’s peak will fall during the night of the day 13, early in the morning of December 14. The waning phase will limit visibility, but the Gemini meteor shower is famous for its big, bright meteors, so a great show still awaits us. The best viewing time is after midnight in a dark place. Meteors tend to radiate from the constellation Gemini, but can appear anywhere in the night sky.
Geminid meteor shower over Heilongjiang province, China, December 2017. Author: Jeff Dai
December 19 – Full moon
The Moon will appear on the opposite side of the Sun as seen from Earth, so its entire surface will be illuminated by the Sun. This phase occurred at 04:37 UTC. The December full moon was first known by Native American tribes as the “Cold Moon” because it was the time when cold air began to appear and the nights became longer. This full moon is also known as the Long Nights Moon and the Moon Before Christmas.
December 21 – Winter Solstice
This year’s winter solstice will occur at 3:50 p.m. UTC. At that time, the Earth’s South Pole will be tilted toward the Sun and the Sun will be at its farthest position in the southern sky during the year, and its light will shine perpendicularly onto the southern Tropic of Capricorn at the southern latitude. line 23.44 degrees. It is the start of winter in the northern hemisphere (winter solstice) and summer in the southern hemisphere (summer solstice).
December 21 and 22 – Ursid meteor shower
The Ursids are a small meteor shower with a frequency of 5 to 10 per hour, formed from dust particles left behind by the remains of comet Tuttle, discovered in 1790. The Ursids meteor shower usually occurs from December 17 to 25 of each year. This year’s maximum will fall on the night of the 21st and early morning of the 22nd, coinciding with the waning moon phase at the beginning of the month, creating obstacles to observations. However, if you are patient enough, you will still be able to see some of the brighter stars. The best time to view meteor showers is after midnight, when the Moon has set and in a dark area, away from city lights. Meteor showers usually originate from the constellation Ursa Major, but can also appear anywhere in the night sky.
Urisd meteor shower 2020. Photo: Jaime McLeod
See more 2021 ephemeris here: https://deepsky2000.net/lich-cac-su-kien-thien-van-nam-2021/
HAS translation team