by Erich Karkoschka

During early dusk, Mercury can be spotted in the southwest after the 12th, but only if you are experienced in finding it.  On the 21st, Spica is only 1 degree from Mercury, seen in binoculars.

Venus is brilliant and rises before 3 am so that it is 40 degrees
high by sunrise.  It races through Gemini, Cancer, and Leo, as the winter constellations take the stage nearby.

Finally, there is a special occultation of Acrab by the moon on
the 21st.  Tucson is located in the middle of the visibility area.
Is it special because Acrab is a bright star, second magnitude and it is a binary separated by 14 arc-seconds.  So in a telescope one can watch the events for both components happening within seconds. Disappearance will be at 6:20 pm local Tucson, which is at sunset, when Acrab is easily visible in a telescope.  Reappearance will be at7:36 pm.

Full Moon: September (1); Last Quarter (10); New (17); and First Quarter (23).

Mars rises at 9 pm at the beginning of the month but already at
7 pm at the end, when it is even brighter than Jupiter.  It is even
more outstanding considering that no other bright star is anywhere close to Mars.  At mid month it becomes stationary and starts its opposition retrograde motion.  Its diameter increases from 19″ to 22″, perfect for viewing in a telescope.  After October, we will have to wait 15 years before it gets such good again. On the 5th, the moon will pass within half a degrees of Mars around 9pm.

Jupiter and Saturn are well up all evening, still setting aftermidnight.  Saturn is 8 degrees east of Jupiter all month.
They are stationary mid month.  Saturn’s ring is 23 degrees open this month, the last time it is so open that far for the next 10 years. Callisto’s shadow transits over Jupiter’s disk on the 13th after 11pm. Ganymede’s shadow does the same on the 26th from 7:30 to 11pm.

Neptune comes into opposition on the 11th.  So it can be seen all night through binoculars in Aquarius.  Uranus rises further east around 9pm.