December 5
The Belt's West Anchor
Sun Position
The Sun is in Sagittarius, near 22.8 degrees south declination. The northern tilt of Earth is nearing its maximum away from the Sun; for equatorial observers, days and nights stay near equal year-round.
Sky Highlight
The entire Belt of Orion clears the eastern horizon before 8 PM for most northern observers, and the belt's alignment along the celestial equator means it rises due east and sets due west from any point on Earth, one of the most consistent navigational facts in the sky.
Deep Sky Object
M78, the brightest reflection nebula in the sky, sits about 1,350 light-years away just northeast of Alnitak in Orion; a faint but detectable blue-white glow in small telescopes, it is a cloud of dust lit by two bright embedded stars rather than by its own emission.
Featured Star
Mintaka (δ Ori) is a multiple system about 900 light-years away, combining a hot O9.5II giant and a B1V companion, two entirely different stellar lives sharing the same point of light in the western Belt. Mintaka sits almost precisely on the celestial equator, rising due east and setting due west from every inhabited latitude.
Around This Date
- December 7, 1972Apollo 17 launched on its trans-lunar trajectory; the mission's commander Eugene Cernan would become the last person to walk on the Moon.
- December 11, 1972Apollo 17's lunar module Challenger touched down in the Taurus-Littrow valley, opening the final crewed lunar landing and the only one to carry a professional geologist, Harrison Schmitt.
Mintaka is the belt star that proves the sky is geometric. It will always rise and set from the same compass point, year after year, world without end.