I spend a lot of clear nights viewing the Moon. I find it endlessly fascinating. But for beginners, or those who only explore occasionally, the lunar surface can be a jumble of confusing details. Here are the resources I reach for most often to find my way
A good lunar map is indispensable. The classic choice is Antonín Rükl’s wonderful Atlas of the Moon. Rükl divides the Earth-facing hemisphere of the Moon into 76 lovingly rendered, detailed charts, and presents the libration zones with an additional eight maps. It’s not only a useful atlas, it’s a striking work of art. Sadly, Atlas of the Moon is currently out of print and used copies often fetch premium prices on eBay and in books shops. But don’t despair — if you can’t get your hands one, there are a couple of good alternatives.
First there’s Sky&Telescope’s Field Map of the Moon, which also features Rükl’s handiwork. This big laminated map presents a 22-inch-wide lunar disk divided into four sections that can be folded several ways to allow you to examine a single quadrant, two adjacent quadrants, or the whole lunar disk at once. Unlike Rükl’s atlas, this map has the advantage of being relatively inexpensive and available. There is even a version for telescopes that have a mirror-reversed orientation (refractors and Schmidt-Cassegrains using a “star diagonal” right-angle eyepiece adapter).
A new Rükl alternative is the 21st Century Atlas of the Moon by Charles A. Wood and Maurice J. S. Collins. It has quickly become my go-to field reference. Unlike the Rükl atlas, this one utilizes spacecraft imagery from the Lunar Reconnaissance Orbiter (LRO) to depict the lunar surface with 36 beautifully produced, highly detailed charts covering the entire Earth-facing hemisphere of the Moon. The atlas is spiral bound, which makes it easy for you to use at the eyepiece of your telescope.
Also utilizing LRO data, Sky & Telescope recently produced a pair of lunar globes — one showing the Moon as we’re accustomed to seeing it, in “visible light,” the other using an array of bright colours to display lunar topography. Although pricey, the pair are much more than attractive display items. Both are useful, and provide a great way to get an overview of the Moon and to see lunar features in context.
If you prefer a computerized Moon map, then you can do no better than Patrick Chevalley and Christian Legrand’s Virtual Moon Atlas. VMA is a very powerful piece of software that serves up an impressive array of options and capabilities. One big advantage it has over its print counterparts is that it can display the Moon’s appearance dynamically by taking into account the phase and libration angle. Remarkably, Virtual Moon Atlas can be downloaded for free.
Atlases and charts aside, a lunar library isn’t complete without at least one reference that describes how the Moon came to look the way it does. In my opinion (which isn’t entirely unbiased) the finest, and most up-to-date is Charles A. Wood’s The Modern Moon. Charts and atlases can tell you where to look, but this book tells you why you would want to. It also lets you use your telescope to play lunar geologist without having to leave your backyard.
Finally, if you want to explore the Moon online, you can easily while away many hours with the Lunar Reconnaissance Orbiter Camera (LROC) Quickmap. It’s new, and not all the bugs have been worked out yet, but even so, the LROC Quickmap is an astonishing piece of work that lets you play with all kinds of data sets and create 3-D renderings of craters, generate profiles of lunar features, measure crater depths and diameters, and on and on. Be warned though — once you start playing with it, you might find it difficult to stop!