December will be a busy month. SKIES OF ARIZONA

by Al Schober

Ok, it's December and it's supposed to be cold. But the year 2020 has been anything but normal in so many ways. As I am writing this in mid November it's 70 degrees during the day so all bets are off as to the weather or the temperature. But this matters not anyway because there are 2 very special events in December for you to observe so lets get to it.

Venus is in the morning sky but is starting it's journey lower in the sky and to it's meeting with the sun in early 2021.

Mars, after it's close approach to the Earth in October is fading but still riding high in the sky after sunset this winter. Look for it overhead and towards the south. It will be a little over two years until Mars again approaches the earth and be bright again. But not as close or as bright as in October. It will take sixteen more years for Mars to become relatively next door to us again.

The first really big event involves Jupiter and Saturn in the southwestern sky after sunset. If you have been watching them this summer and early fall you might have noticed that they seem to be moving closer to each other in the sky. They are. Once in a while as the planets sail around the sky two or sometimes three of them will come close together. Jupiter and Saturn will not only be close but extremely close to each other in late December. As December begins they are 2 degrees apart and from the 12th until the 29th they will be within 1 degree of each other!!! That puts them both in the same binocular field and you can watch their moving closer and then receding from each other that way. On the night of December 21st these 2 gas giants will be within 6 minutes of arc from each other. That's very close being within 12 times the apparent diameter of Jupiter away from one another. If you have a telescope that means that both planets will be in the same medium to high power field with Jupiter's 4 moons and a few of Saturn's also visible. How often does this occur? The last time was in the year 1226 and the next time will be far in the future. This will be seen low in the southwestern sky after sunset so you will need a clear southwestern horizon.

Do they ever occult each other? Yes, the last time the planet Jupiter covered Saturn was around 8,000 years ago and in the year 2 BC the planet Venus covered Jupiter on June 17th. Some scholars think that this occurrence might have been the “star off Bethlehem”.

Meteor shower time again!. On Sunday December 13th the Geminid meteor shower graces our night skies. The Geminids are now the best shower of the year surpassing the August Perseid in number of meteors observed. They have bee slowly increasing in the number of meteors seen so thus the “best” of the year. Also you do not have to stay up all night or set your alarm for the early morning hours to see these shooting stars. They seem to come from the constellation Gemini, the twins, which is rising in the east after sunset. There is no moon in the sky this year so conditions are perfect for a great show. Of course the darker your skies the more meteors you will see. Meteors can be seen anywhere in the sky, so look around not just towards the east.

The shower's maximum is predicted to be in the early hours of Sunday evening on the 13th. These meteors are active for a week or so before and after the 13th so you might catch a glimpse of a streak in the sky anytime during this 2 week period. The predictions for the number of meteors you could see is for 150 per hour under dark skies on the night of the 13-14th. Wow. More than 2 a minute with some of them being really bright. Geminid meteors are slow, only hitting the atmosphere at 22 miles per second so they might be visible for a few seconds instead of the brief flash of a Perseid in August. Happy hunting and stay warm out there.

If you have any questions or comments you can reach me at skiesofarizona@hotmail.com

Thanks, Al

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