The week of November 17-23 takes us from Day 28 to Day 4. This week we will highlight the moon crater Furnerius, visible on Sunday night close to the terminator.
Furnerius: [SE/N16; L=61°E] This is the southernmost of the moon craters that make up the Great Eastern Chain. It is very old, having formed before the impact that created the Nectaris basin 3.9 billion years ago. Although the walls have been battered down and show their age, there are still many complexities remaining which will reward careful observation. There are several craterlets of varying sizes on the floor of Furnerius, including a 30-mile rille extending from the north rim toward the southeast. Patrick Moore reported that there are fourteen large craters and several craterlets in its interior. (A more reasonable assessment would be there is one large crater and several craterlets.) Make a rough sketch of how many you can see, then come back next month (and on Day 17) to see if you can add to the count. Can you match Patrick Moore’s observing skills?
OF ADDITIONAL INTEREST IN SPACE
Leonid meteor shower peaked on Monday night.
Furnerius A: [SE/N15; L=62°E] On Day 3 we introduced you to Furnerius A and asked you to keep an eye on its ray system throughout the lunation. Furnerius A is only 7 miles in diameter but produces a ray that extends for 1,200 miles! How is it that such a tiny crater can splash its debris over nearly half of the Moon’s surface! Tonight, the entire length of the ray should be clearly visible. (Look closely on the Field Map for the tiny arrow that points out Furnerius A; it’s easy to miss.)
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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]
Credits:
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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