December ISS and Sky Happenings
By Chuck McPartlin
The International Space Station will be making a few visible passes through Santa Barbara’s evening skies in early December. Its orbit may change from time to time, so to get the latest and most complete predictions, visit Heavens Above.
On Saturday, December 5, the space station will make a very low pass over our mountain horizon, rising in the N at 5:53 PM PST, passing along the back of Ursa Major, the Great Bear, and fading out into the Earth's shadow at 5:55 PM in the NNE in dim Camelopardalis, the Giraffe.
On Sunday, it will pop up briefly in the NW at 6:41 PM, climbing to an altitude of 26 degrees, and vanishing at 6:43 PM by the head of Draco, the Dragon. His head asterism is known as the Lozenge.
Monday's ISS pass will be bright, rising at 5:54 PM in the NNW, passing below Ursa Minor, the Little Bear, across Camelopardalis and Perseus, and then through the bright open cluster of the Pleiades, the Seven Sisters, in the E where it will enter our shadow at 5:58 PM. Photo op!
On Tuesday it will rise in the WNW at 6:43 PM, cruise below the Summer Triangle of Vega, Deneb, and Altair, then above dim Capricornus, the Sea Goat, and fade away in the SSW at 6:47 PM as it nears Fomalhaut, the mouth of Piscis Austrinus, the Southern Fish. Fomalhaut is often called The Lonely One, since it is the only bright star in that part of the sky.
The pass on Wednesday will be the highest bright pass of this short series, starting at 5:55 PM in the NW, going below bright Vega, past Enif, the nose of Pegasus, the Flying Horse, and ending at 6:02 PM at our SE horizon below Deneb Kaitos, the tail of Cetus, the Sea Monster.
There will be no passes on Thursday evening, but the ISS will make a dim farewell to our evening skies for 2020 on Friday, December 11, appearing at 5:57 PM in the W, and disappearing in the S at 6:02 PM after passing very close to bright Jupiter, closely paired with Saturn.
The ISS will then transition to a series of early morning passes, returning to our evening sky in mid-January.
The Sky for December
If the skies are clear, December nights are dark and crisp. The Andromeda Galaxy is overhead, the Summer Triangle is sinking in the west, and Taurus and Orion dominate the east. Globular clusters are few, but showy open clusters like the Pleiades and the Double Cluster are well placed.
On Saturday, December 12, watch in binoculars or a telescope as the Moon occults Venus. For us, a bright gibbous Venus slips behind the slim sunlit crescent of the Moon at about 1:15 PM PST, and pops out again on the shadowed side at around 2:30 PM. At the start, they will be about 21 degrees up in the southwest, at an azimuth of 228 degrees.
The Geminid meteor shower will peak on the evening of December 13/14, with no Moon to interfere. The predicted peak starts at 5 PM, so it should be good all night. The Geminids rival the summer Perseids in their hourly rate, and have a high proportion of fireballs because they are rocky fragments of asteroid 3200 Phaethon. As you might suspect, the radiant point is in Gemini, near the head stars Castor and Pollux, and will be nearly overhead at midnight. Hope for clear skies!
At sunset on December 16, the crescent Moon will be near the close pair of planets Jupiter and Saturn low in the southwest.
On Monday, December 21, the northern hemisphere's Winter Solstice will occur at 2:01 AM PST. Welcome to Winter! Then, low in the southwest at sunset, Jupiter and Saturn will have a magnificent close conjunction at less than a tenth of a degree separation. Both gas giants and their brighter moons will be visible in a typical telescopic field of view, although Ganymede will be transiting the face of Jupiter. This is the closest they've been since 1623, but the last time they were easily visible in such a close conjunction was in 1226.