Welcome to the University of Texas Skywatchers Report for Monday December 21, 2020 through Sunday January 3rd, 2021.
The moon is at first quarter on Monday the 21st and then we’ll have a waxing gibbous moon until we reach the full moon late on December 29th. The Full Moon for the month of December is known as the Long Night Moon and the Moon Before Yule.
After moving closer to each for many months, Jupiter and Saturn will be one tenth of a degree apart on Monday the 21st, which is the closest they’ve appeared in our skies in 400 years, although that time they would have been hard to observe because they were very close to the sun. The last time people would have easily seen the two planets this close together would have been 800 years ago. To see the conjunction this year, find a spot with a clear view of the western horizon and look to the southwest. The pair will set at 7:50 p.m., a little over two hours after sunset. After the 21st, the pair will start to drift apart again and will soon be lost in the Sun’s glare as they head towards their solar conjunctions early next year.
Mercury is moving away from the Sun but will still be lost in the sun’s glare as we finish the year.
Mars is high in the southeast as the sky darkens after sunset and is setting at 2:00 a.m. on the final day of 2020.
Venus will continue moving towards the Sun as we finish out 2020. Venus will be rising 90 minutes before the sun on December 31st.
The winter solstice will be at 4:02 a.m. on December 21st when we will have a total of 10 hours and 11 minutes of daylight here in Austin. Compare this to a 12 hours and 8 minutes at next year’s vernal equinox and 14 hours and 6 minutes on the summer solstice.
The Earth will be at perihelion, it’s closest point to the Sun in its orbit, on January 2, 2021 when it will be 91.4 million miles from the Sun. Compare that to the distance at aphelion on July 5th, 2021 when it will be 94.5 million miles from the Sun.
All public viewing events on UT campus telescopes will be on hold through the Spring 2021 semester. We will update the website outreach.as.utexas.edu with a new schedule when we are able to resume viewing.
While you’re waiting for in-person telescope viewing to resume, you can tune in to McDonald Observatory live streams from west Texas. You can view past events on the McDonald Observatory YouTube channel and you can follow the observatory on Twitter, Facebook and at McDonaldObservatory.org to be notified of future events.
Thank you for calling the University of Texas Skywatchers Report and have a happy and safe holiday season.