Welcome to the University of Texas Skywatchers Report for Monday December 20, 2021, through Sunday January 2, 2022.
The moon was full late on Saturday the 18th and then we will have a waning gibbous moon through to the end of Sunday the 26th when we’ll reach third quarter. After that, we’ll have a waning crescent moon in the early morning skies until we reach new moon on Sunday January 2nd as we start the new year.
Mercury will continue to move away from the sun as we finish out 2021 as it moves towards its next greatest elongation a week into the new year. Mercury will set at 6:20 p.m. on the 20th and will be setting at 7:00 p.m. at the end of the year.
Venus will still be shining very low in the west-southwest at sunset and will be moving back towards the sun and its next conjunction early in 2022. Venus is setting at 7:35 p.m. on the 20th and at 6:45 p.m. on the 31st, just an hour after sunset.
Saturn is low in the west-southwest at sunset and is setting at 8:40 p.m. on December 20th and at 8:10 p.m. at the end of the year.
Jupiter is also quite bright in the west-southwest but is higher and to the left of Venus and Saturn. Jupiter is setting a little after 10 p.m. on the 20th and is setting at 9:30 p.m. on December 31st.
In the southeast in before dawn, Mars is rising at 5:35 a.m. on December 20th and just a few minutes earlier by December 31st. A very thin crescent moon will be alongside Mars on the final morning of 2021.
The winter solstice for the northern hemisphere occurs at 9:59 a.m. on December 21st for those of us in the US central time zone. This is the day that the sun reaches its farthest point south of the celestial equator so it will make its smallest arc through our skies that day and we will have the shortest amount of daylight. Here in Austin, the earliest sunsets occurred from late November into early December when the sun was setting at 5:30 p.m. and the latest sunrises occur for us in early to mid-January when the sun rises at 7:28 a.m. On the December solstice, Austin will have our smallest amount of sunshine at 10 hours 11 minutes and 38 seconds. Compare this to 14 hours and 6 minutes at the summer solstice in June, when we get our greatest amount of sunlight in the year.
Public viewing on UT campus telescopes has finished for 2021. For now, we are planning to resume spring semester viewing as usual in late January 2022, but please check back in early 2022 for more details.
Thank you for calling the University of Texas Skywatchers Report and best wishes for 2022!