The week of April 10 – 16 takes us from lunar Day 14, full moon, to Day 20. This week we will highlight the crater Humboldt on Tuesday evening (you might try Monday to see if there’s enough contrast), and Promontorium Agarum on Wednesday.
• Humboldt: [SE/M18] This crater is best viewed when there is a pronounced libration (as will be the case on Tuesday). Because of foreshortening, it appears to be extremely elongated north to south. It has a cluster of central peaks, and if you’re lucky you might spot a long catena (crater chain) extending from the northeast rim of the crater.
• Promontorium Agarum: [NE/H16] (On Wed., the Moon rises at around 9:00 PM so wait until 11:00 or midnight). This is an impressive cape on the SE edge of Mare Crisium. It has peaks which rise to several thousand feet above its floor. Lunar Transient Phenomena (LTP’s) have occasionally been reported in this region. Don’t hold your breath, but keep the possibility in mind.
OF ADDITIONAL INTEREST NEAR THE MOON ON LUNAR DAY 14 – DAY 20:
If you have chosen to view the Moon this week in the early morning hours, Comet Lovejoy is a nice add-on. It was predicted to be only 9th magnitude, but has brightened to 7th. Its visible in 50mm binocs at around 4:40 AM just over the horizon, 4° to the left of Beta Pegasi.
It is highly recommended that you get a copy of Sky and Telescope’s 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]
Courtesy of Gray Photography of Corpus Christi, Texas
Lunar photos: NASA / USGS / BMDO / LROC / ASU / DLR / LOLA / Moon Globe. Used by permission
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