December 4 – Mercury reaches its maximum eastern ecliptic
Mercury reaches its maximum eastward elongation, up to 21.3 degrees from the Sun. This is the best time to see Venus as it will be at its highest point above the horizon in the evening sky. Look for this planet in the western sky after sunset.
December 13 – New Moon
The Moon will be on the same side of Earth as the Sun and will not be visible in the night sky. This phase occurs at 06:33 (Vietnam time). This is the best time of the month to observe faint objects like galaxies and star clusters that will not be affected by moonlight.
December 13-14 – Geminids – Meteor Shower
The Geminids are the kings of meteor showers. It is considered by many to be the most splendid shower in the sky, producing up to 120 meteors per hour in a multitude of colors at its peak. It was created by the debris left by the asteroid 3200 Phaethon, discovered in 1982. Rain falls every year from December 7 to 17. This year, the peak is on the night of 00:14. This year, the new moon will leave a perfectly dark sky. Viewers are best viewed from a dark location after midnight. Meteors will radiate from the constellation Gemini, but can appear anywhere in the sky.
December 22 – Winter Solstice
The winter solstice occurs at 10:21 a.m. The South Pole of the Earth will be tilted towards the Sun, and the Sun will reach the southernmost position in the sky, located just above the Tropic of Cancer at 23.44 degrees south latitude. It is the first day of winter (winter solstice) in the northern hemisphere and the first day of summer (summer solstice) in the southern hemisphere.
The Northern Hemisphere receives less sunlight at the winter solstice. Photo: Wikipedia
December 21 and 22 – Ursids, meteor shower
The Ursids are a small meteor shower that produces about 5-10 stars per hour. It is created by dust particles left behind by Comet Tuttle, first detected in 1790. The rains occur every year from December 17 to 25. This year, the peak is on the night of the 21st, at dawn on the 22nd. This year, the closest-full moon will eclipse most of the weak and medium meteors. The best sighting would be shortly after midnight from a dark location away from city lights. Meteors will radiate from the constellation Ursa Minor (Little Dipper), but can appear anywhere in the sky.
December 27 – Full Moon
The Moon will be on the opposite side of the Earth to the Sun and its face will be fully illuminated. This phase occurs at 07:34 UTC. This full moon was called the Cold Moon by the early Indian tribes because it was the time of year when the cold winter air came in and the nights grew long and dark. This moon is also known as the Long Night Moon and the Pre-Christmas Moon.
The year 2023 is therefore over, I hope you had a good year!
See more Ephemeris 2023 here: https://deepsky2000.net/lich-cac-su-kien-thien-van-nam-2023