January 31
The First American Orbit
Sun Position
The Sun lies in Aquarius, about 17.8° south of the celestial equator. In the Northern Hemisphere the days are still short but lengthening; in the Southern Hemisphere this is high summer with long, warm evenings.
Sky Highlight
Alnilam, the central star of Orion's Belt, is a blue supergiant whose light left it over a thousand years ago. The belt sits squarely on the celestial equator, shared by all the world.
Deep Sky Object
The Horsehead Nebula (Barnard 33), a dark column of dust silhouetted against glowing gas near Alnitak, about 1,400 light-years away. A challenging target for both hemispheres.
Featured Star
Alnilam (ε Ori), a blue supergiant in Orion, about 1340 light-years away. Alnilam, the middle pearl of Orion's Belt, a supergiant of enormous power.
Around This Date
- January 31, 1958Explorer 1, the first U.S. satellite, launched and discovered the Van Allen radiation belts.
- January 31, 1971Apollo 14 launched with Alan Shepard, Stuart Roosa, and Edgar Mitchell, Shepard, the first American in space a decade earlier, would become the fifth human to walk on the Moon.
The middle star of the belt has been pouring out light since before the telescope.