Incredible video shows the Moon as we’ve never seen it before: rotating (VIDEO)
posted Tuesday, September 17, 2013 at 1:21 PM EDT
One of the wonderful peculiarities of the Moon is that it's tidally locked facing the Earth. What that means is that only one side of the satellite ever faces our planet — there isn't a dark side of the Moon, but there is a far side that we don't get to see. So while the Moon does rotate much like the Earth, it does it in such a way that we can't observe from our spot on the surface of the planet. But a new video released by NASA gives us a glimpse at something we've never seen before — our Moon spinning like a top.
Posted on NASA's Astronomy Photo of the Day page, the short video is a combination of footage taken from the Lunar Reconnaissance Orbiter (LRO). It condenses an entire Lunar month into just 24 seconds of swiftly rotating video.
For more on how it was shot, there's information on the LRO's site. Because the LRO's wide angle camera (WAC) has an extremely wide field of view (90°), it wasn't a simple matter of just stitching together a couple of images. Instead, they had to:
take 36 nearly complete global mosaics (110,000 WAC images) and determine an equation that describes how changes in Sun angle and view angle result in reflectance changes. Next step, for each pixel in those 110,000 WAC images compute the Solar angle and the viewpoint angle (using the GLD100 to correct for local slopes), and adjust the measured brightness to common angles everywhere on the Moon.
They also have a longer, two-minute, high resolution video of the rotation there, if you want to see it in more detail.