In mid-December, stargazers can expect several highlights:

- December 15: Altair disappears; Algol dims at 9:58 p.m. EST.

- December 16: The waning Moon rises with Pollux and Castor.

- December 17: The Moon is above Mars, and Io transits Jupiter at 7:05 p.m. EST.

- December 18: Sirius rises around 8 p.m.

- December 19: The Moon is near Regulus, and Jupiter’s moons form a triangle at midnight.

- December 20: Sirius and Procyon appear as Saturn approaches Venus.

- December 21: Winter solstice, marking longer days.

https://skyandtelescope.org/astronomy-news/observing-news/this-weeks-sky-at-a-glance-december-13-22/