Dark Sky News

Jupiter takes over from Saturn and enters the spotlight, with Mars not too far behind!  By month’s end, Mars will be only two weeks from its January 16 opposition!

Don’t miss seeing Jupiter in Taurus, at magnitude -2.8 and 48.21″ diameter. It’s maximum diameter is 49.9″ so this is a pretty good size for both observing and imaging! The red spot should be visible right in the center of Jupiter at 9:10pm, so this is a perfect opportunity to see it!

Unlike a majority of the meteor showers we see on Earth, the Geminids are the product of an asteroid, not a comet, specifically the asteroid 3200 Phaethon.  Geminids meteors are often bright, intensely colored, and slower-moving than average.  True Geminids will appear to streak away from a position near Gemini’s bright stars Castor and Pollux, but the meteors can appear anywhere in the sky, so just keep looking up and around. Usually you can see up to about 120 meteors an hour, but this year’s shower will unfortunately be hampered by bright moonlight.

At 4:21am EST.

Yay! The longest astroimaging night of the year! Ok am I the only one who’s happy about that? Well may be David too. At the solstice, the sun will attain its southernmost declination for the year, resulting in the lowest elevation in the sky of the noonday sun, the least amount of solar insolation, and the shortest amount of daylight of the year. 

At 2:48 a.m. Eastern Time (or 07:48 GMT), the red spot and the small shadow of Io will join the much larger shadow of Ganymede, which began its own crossing of the planet’s south polar zone 70 minutes earlier. Ganymede’s shadow will leave Jupiter at 3:48 a.m. EST (or 08:48 GMT), leaving Io’s shadow and the spot to continue on alone until 4:58 a.m. EST. Watch for Io itself to move off of Jupiter’s disk by 4:35 a.m. EST.