The week of December 2 – December 8 takes us from Lunar Day 2 to Day 8. This week we will highlight Rima Hyginus, visible on Saturday night.
Rima Hyginus: [NE/J10; L=8°E] At the west end of the Ariadaeus rille, there is a narrow diagonal shunt that connects Ariadaeus to Rima Hyginus. This new rille parallels Rima Ariadaeus for about 20 miles, then continues west until it encounters the small 6-mile crater Hyginus. At that precise point, it changes direction and veers northward toward Mare Vaporum. The fact that the Hyginus moon crater is located precisely at the pivot point is a curiosity. Can this just be coincidence?
Rima Hyginus is 2.5 miles wide and is easily seen in very small telescopes. It is really made up of a line of linked craters, which are best seen just northwest of the moon crater Hyginus. With good optics and steady seeing, you might be able to make some of these out even with a three-inch scope. Wood suggests that these are actually rimless collapse pits of internal origin and that the moon crater Hyginus (also rimless) might be one of their number. Can you see any of the individual craters, or does Rima Hyginus just look like a linear feature?
OF ADDITIONAL INTEREST IN SPACE
On Wednesday, Venus is 2.3° north of the Moon.
On Sunday, Saturn is 0.3° south of the Moon.
Field Map of the Moon, the very finest Moon map available for use at the telescope. It is available for $10.95 at www.skyandtelescope.com and on Amazon. All features mentioned in this blog will be keyed to the grid on the Field Map and will look like this: Plato: [NW/D9]
Credits:
Courtesy of Gray Photography of Corpus Christi, Texas
Lunar photos: NASA / USGS / BMDO / LROC / ASU / DLR / LOLA / Moon Globe. Used by permission
- Altai Scarp (Rupes Altai) – How Shock Waves from a Major Impact can Compress the Surrounding Terrain - January 13, 2025
- Most Spectacular Feature on the Moon – Apennine Mountain Range - January 6, 2025
- Trio of Moon Craters, Theophilus, Cyrillus,and Catharina - December 30, 2024