December 1
The Red Eye Opens
Sun Position
The Sun is in Sagittarius, sitting at roughly 22 degrees south declination and descending toward the winter solstice. Northern Hemisphere days are short and contracting; Southern Hemisphere days are long and near their peak.
Sky Highlight
December opens with Taurus riding high in the east by mid-evening, carrying the Pleiades and Hyades clusters into fine viewing position. No major meteor shower peaks today, but the Geminid radiant is building in the northeast, setting up the month's best shower two weeks out.
Deep Sky Object
M45, the Pleiades (open cluster in Taurus, about 440 light-years away) is nearly overhead for mid-latitude northern observers by 10 PM and well-placed in the northern reaches of the southern sky too; the cluster's blue-white stars and their faint associated nebulosity reward both naked eye and binoculars.
Featured Star
Aldebaran (α Tau) is a K5III red giant about 65 light-years away, a true giant nearing the end of its hydrogen-fusing life with a diameter roughly 44 times the Sun's. It is the red eye of the bull, and it has followed the Pleiades across human skies since before writing existed.
Around This Date
- December 3, 1973NASA's Pioneer 10 became the first spacecraft to fly past Jupiter, returning the first close-up images of the giant planet and surviving a radiation environment far harsher than anticipated.
- December 6, 1998Shuttle mission STS-88 connected the Unity module to the already-orbiting Zarya module, completing the first structural assembly of the International Space Station.
Aldebaran has watched every December since the Pleistocene; it will still be watching long after the last calendar is made.