The Moon’s pole, in context

The Moon’s pole, in context

The Moon’s pole, in context

Bad Astronomy
The entire universe in blog form
Nov. 14 2007 2:51 PM

The Moon’s pole, in context

Note: Discovery HD will be showing the Kaguya Earthrise video in high-def format tonight (Wednesday) at 8:00 p.m. Eastern time!

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

When I posted the Earthrise picture last night, I was so gung-ho on the images themselves (and how dark the Moon looks) that it didn't occur to me to think about the lunar landscape itself. Trust my old buddy and planetary/asteroid/moon expert Dan Durda to actually examine the surface and determine what you're seeing (click to embiggen):

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The big crater is Shackleton, and is 19 km across (roughly the size of Washington, DC). The other crater labeled is a little over a kilometer across, the same size as Meteor Crater in Arizona. A few years ago I stood on the rim of Meteor Crater in Arizona and marveled at the size of it... yet look at how dinky it is in comparison to Shackleton! And keep this in mind: Shackleton is a relatively small crater on the Moon. Tycho, for example, is 85 km across. Clavius is well over 200 km across.

Shackleton is special, though. It sits right on the Moon's south pole. Parts of its rim stick up so high off the surface that they are almost always in sunlight, all the time. The Sun would never set for, say, a series of solar panels situated there. Weirdly, for parts of the crater floor, the Sun would never rise, and there is some evidence (still shaky, and not confirmed) that there may be deposits of water ice there. That's why NASA is interesting in exploring this region of the Moon. It would make a great place to set up a power station for any future base, and might also be a supply of water. A twofer!

Pictures like this really bring home -- so to speak -- how alien and different the Moon is from the Earth.