My photo of a three day moon. East is at the bottom. Mare Crisium is the egg-shaped feature on east limb.

Here's my photo of a five-six day moon, near first quarter. East is at bottom here too. The middle [...]]]>

Lunar Landing Site Chart - click for larger versions. Courtesy Lunar and Planetary Institute

My photo of a three day moon. East is at the bottom. Mare Crisium is the egg-shaped feature on east limb.

Here's my photo of a five-six day moon, near first quarter. East is at bottom here too. The middle sea visible above/West of Mare Crisium is the Sea of Tranquility, site of the Apollo 11 landing.

Here's my photo of a fourteen day or full moon. East is at the top. Notice the features are less distinct, but look for the long rays spreading out from the two large craters Copernicus (lower middle left) and Tycho (lower right).

Finally, my photo of a 21 day or third quarter moon. West is at the bottom left

Fasten your seat belts. I’m going to take you on a guided month-long tour of the moon and highlight some of my favorite lunar features. You can use this travelog all year to observe or sketch the moon any time the moon is visible. You’ll be surprised how some of the familiar geology you’ll see on our rocky neighbor changes as sunrise or sunset illuminates different sides of crater walls. If you don’t have a moon map, click on the one to the left, or the other one at the bottom.

The visible features I describe will be illuminated by sunlight from the right to the left as shown on this moon chart. It takes 14 days from new to full moon. At full moon the entire disk will be illuminated, then sunset darkens the features night by night, from right to left. Try viewing the same features before, during and after the full moon.

New Moon Phase Day 1 – 6 The moon rises at dawn, and sets at dusk. The new moon phase starts at solar conjunction. This is the starting point of the lunation or period of the Moon’s cycle around the sky. Day 1 is very difficult to observe. On day 2, the “sea” of Crises, Mare Crisium becomes visible. To the south is Petavius, a large crater with a central peak of over 8000 feet. Day 3 brings Mare Fecunditatis, south of Mare Crisium, into view. On day 4, Mare Crisium and Mare Fecunditatis are fully visible, and the walled plain Janssen is visible. On day 5, Theophilus, Cyrillus and Catharina make a nice group of craters. The crater Maurolycus, with a central peak like Theophilus, appears on day 6. The moon is now approaching first quarter. The terminator (boundary between the sunlit and dark parts of the moon) is now at the center of the moon’s disk.

First Quarter Phase Day 7 – 13 The moon rises at noon, and sets at midnight. The crater Hipparchus is at its visible best near the terminator on day 7. Look for two craters within Hipparchus. Day 8 brings into view the rugged Appenine mountains, and to the north the oval walled plain Plato. With binoculars or telescopes, find the “Straight Wall”, a lunar fault line. Tycho and Copernicus are on the terminator on day 9, and so is Clavius, the large walled plain south of Tycho. On day 10 look for the Jura Mountains and Sinus Iridum (the bay of rainbows) with its hook-like curved mountainous point on the edge of Mare Imbrium. This is one of my favorite objects on the moon to observe and sketch. On day 11, look back on the whole moon and observe the dark lunar lava plains divided by mountains. On day 12, look at Gassendi, a large crater with a smaller crater next to it. Together they look like a diamond ring. As full moon approaches, look back over the objects you observed each night and see how different they look.

Full Moon Phase Day 14 – 21 The moon rises rises at dusk, and sets at dawn. Look at the bright ray systems. The direct sunlight on the moon at this phase washes out features, and you see no shadows, just like when the sun is directly overhead on earth. The long rays of Tycho are most dramatic at full moon! Day 15 brings sunset to Crisium, 2 weeks after we first viewed its sunrise. Watch the shadows cast on the walls of the plains including the darkened Mare Crisium, and craters on day 16 through 18. Day 19 is a good one to view the “Sea” of Tranquility, famous as the landing site of Apollo 11. There is a link to lunar landing sites at the bottom of the page, by the way. Day 20 brings the terminator to another of my favorite observing and sketching sites, the three craters Theophilus, Catharina and Cyrillus. Mountains are the highlight of day 21. The Apennines, and the large craters Kepler, Copernicus and Tycho are beautiful at lunar sunset. The last quarter moon has arrived.

Last Quarter Moon day 22 -27 The moon rises at midnight, and sets at noon. You really have to be dedicated to view this phase, or maybe just sleep deprived. Mare Imbrium and Copernicus are darkening on day 23. On day 24 through 27, most observers are sleeping when the moon is visible. Use binoculars to observe earthshine over the surface of the moon. These are the days (or rather nights) to turn your eyes, binoculars or telescopes to other wonders of the night sky: planets, comets, meteor showers and galaxies. Say good-night to our close neighbor. If you didn’t catch all these features, there’s always next month!

A moon map with almost all the features labelled

Check out all 6 Apollo landing sites, plus moon phase/landing site maps on this flyer I made for the GRAIL mission launch week in September 2011. (PDF)

USNO’s great Phases of the Moon and Percent of the Moon Illuminated pages

Here’s the original 1990 article I wrote for John Dobson’s Sidewalk Astronomy newsletter. My mom contributed the adorable lunar drawings.

My Sketches at the Eyepiece website

finished sketch of Cabeus and environs

E. A. Whitaker 1954 sketch

Mojo and I started to setup his 14.5-inch f/4.8 Litebox reflector at 3:30 a.m. on LCROSS impact morning. There were marine layer clouds at that hour, but by the time we were set up it was clear [...]]]>

Rough sketch of LCROSS impact area

finished sketch of Cabeus and environs

E. A. Whitaker 1954 sketch

Mojo and I started to setup his 14.5-inch f/4.8 Litebox reflector at 3:30 a.m. on LCROSS impact morning. There were marine layer clouds at that hour, but by the time we were set up it was clear overhead. Friends deeper in the LA basin were fogged out completely!

I thought the seeing was not too bad — I was expecting a lot worse. I was able to use pretty high magnification — a 6mm Televue Radian which magnified the view 276 times. I increased the power to 446X using a 4mm Televue Radian, but that was a little too much magnification for the seeing conditions. My first “signpost” to Cabeus was the beautiful walled plain Clavius, with its semi-circle of craterlets on the floor. Two big craters called Rutherford and Porter, named for famous American astronomers, are on the wall of Clavius. There was no shadow relief, making the whole crater nearly invisible.

Then I crater hopped to Moretus, Short, Newton and finally Cabeus. Little bumps on the limb made the crater ID easy, plus I’ve been studying those images for days. Those bumps are mountain peaks on the huge South Pole-Aitken basin, obscured from our view, except for a few peaks on the south limb.

A slick white smear on the sunlit Cabeus crater wall bisected the elongated crater. You can see it on the – APOD lunar chart just above the red ellipse identifying Cabeus. It was really fun to watch the approach from the LCROSS camera on NASA TV, then scoot out the front door for views of the crater itself through our own telescope. I was looking at Cabeus at impact time and didn’t see (and didn’t expect to see) a plume. I recalled the night in 1999 when Mojo and I spent a night waiting and watching the South pole of the moon for the Lunar Prospector impact.

Some final thoughts a few days after LCROSS impact. The GAVRT radio telescope in the Mojave desert of California was abuzz with school kids around the world tracking LCROSS. The students locked onto the LCROSS signal and passed the information on to mission control. They will never forget this exciting mission and their important contribution to it! I was really impressed with the LCROSS mission E/PO and citizen science program which encouraged thousands of amateur astronomers like me to follow the mission, prepare an observing program and report observations.

Although sketches are not the same as video and images, I like thinking that I was sketching an area of the moon in the 400+ year old tradition of citizen scientists. The LCROSS mission follows in the tradition of trailblazing lunar missions. In fact, the mountain peak called M5 on Ewan Whitaker’s 1954 lunar map (on the limb south of Cabeus) is now named Mount Clementine!

nine-day moon

Lunar creature features

Rabbit on the full moon

Night owls can enjoy the nine-day moon – it’s up all night long. In my sketch, the magnificent crater Copernicus is visible on the sunlit side of the terminator – on the right side of the lunar center. It looks so insignificant right now, but [...]]]>

nine-day moon

Lunar creature features

Rabbit on the full moon

Night owls can enjoy the nine-day moon – it’s up all night long. In my sketch, the magnificent crater Copernicus is visible on the sunlit side of the terminator – on the right side of the lunar center. It looks so insignificant right now, but at full moon, its spendid ray system is a naked-eye delight! Tonight you see the deep crater floor half lit by the sun. Here’s a closeup of Copernicus sketched through a larger telescope at higher magnification (185x versus 19x on these full disk drawings) on nearly the same day of the lunar month.

From now until full moon, the dark lunar mare start to resemble creature features. I see half of the rabbit on the moon in my sketch. Mare Fecundatis and Mare Nectaris make the ears and Mare Tranquillatis (the Sea of Tranqulilty) makes a cute little bunny head. You can see other creatures in my February 2009 What’s Up podcast about the moon, linked below.

As we near the full moon, the sun angle is more direct and crater wall shadows disappear. There are some other craters on the terminator tonight, which will reveal their amazing ejecta rays in a few more days when the moon is full. Towards the left edge of the terminator, Tycho is half lit now, but at full moon, its rays extend 1000 km. The spectacular walled plain Clavius is just starting to reveal its beauty. Through a telescope, when the entire crater is visible, you’ll see a dozen smaller craters on its floor.

My What’s Up Podcast, July 2007: The phases of the moon

My What’s Up Podcast, February 2009: Galileo’s and other first views of the moon through a telescope

My photo of the nine-day moon