Moon-Venus-Saturn-Antares in the mornings to come

John Goss has an excellent short survey of astronomical 2016 in the column he writes for the newspaper of his region of Virginia. He warns against over-hyped “super-Moons,” and starts with the “planetary action in the pre-dawn hours [which] by late winter shifts to the evening sky.”

That early planetary action is detailed in the Astronomical Calendar page for January, but here we can show it on a larger scale.

Morning sky 2016 January 6

Since four bright bodies are involved, there will be a multiplicity of conjunctions, mostly during the night of Jan. 6/7. Over a space of about 6 hours, the Moon will pass north of all the others, and Venus north of Antares.

Antares lies 6 degrees or so off the path of the three moving bodies, but those three get themselves into a “trio”: a concentration within a circle of less than 5 degrees. The minimum diameter – maximum concentration – reaches 3.6 degrees. In case you’d like some more of the numbers that my program was able to cough up: the separations at this moment between the Moon (that is, its center, as seen from the center of the Earth) and Venus is 3.36°, Moon-Saturn 3.42°, and Venus-Saturn 2.26°, and the group hovers roughly 36 degrees from the Sun. But: this comes about at 4 Universal Time (11 PM in eastern North America on Jan. 6), deep in the night for our side of the world. So we have to be content with seeing the trio in its almost-as-concentrated states on the mornings before and after.

Two nights later, Jan. 8/9, Venus passes Saturn at a distance of only 0.08 degree. This is the second closest planet-planet conjunction of the year, but its climax, too, happens at 4 UT (11 PM EST), so we have to see Venus just up-right from Saturn on the morning of the 8th, just up-left of it on the morning of the 9th.

(The arrows through the planets show their motion from 2 days before to 2 days after picture time, so you can see how rapidly Venus moves compared with distant Saturn.)


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