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The annular eclipse of May 20 as seen from the Moon

What does a solar eclipse look like from the Moon? The LROC NAC captured four images of the Earth, two on each of two successive orbits, during this solar eclipse. In these images you can see the Moon’s shadow passing over the Earth over a period of about two hours.

The LROC NAC cannot easily acquire images of the Earth as requires a significant amount of planning. The NAC is a line scanner, meaning that it has only one row of 5064 pixels per camera. Instead of snapping a single frame, an image is built up by the motion of the spacecraft in orbit about the Moon (about 1600 meters per second).

To obtain an image of the Earth the spacecraft is turned 180° to face the Earth, then the spacecraft is pitched as quickly as possible, so that the image is built up line by line. You can see that two of the frames in the animated image are slightly clipped, because LRO’s timing wasn’t perfect and the NAC ran out of lines before completing the scan.

Because it was an annular eclipse, the shadow isn’t totally dark; some sunlight still made it down to viewers of the eclipse as it passed over. The paneled image provides a zoomed in view of the Moon’s shadow. »