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A second version of Lunar Libration. For this one I added a phase, and an Earthlight effect.

The Moon changes more than people think - it varies its distance from the Earth, and thus its apparent size. It also 'rocks' as it spins evenly, but the elliptical orbit means that you sometimes see more of the left edge, sometimes the right. These motions are called LIBRATIONS.

This animation shows the maximum degree of libration, and also the degree of variation in size. The real motion is not as simple as this loop, but the degree of rocking is accurate.

1080p HD, displacement mapped Moon.

Newspapers periodically talk of things like the largest full moon of the year - as this video shows, the maximum is only about +5% more than the average, it's very hard to spot unless you know what to look for.

It is enough to make the moon sometimes a bit smaller than the Sun, which is what drives an annular eclipse, when you get a fine ring of light all around the Moon, but no totality.

If you want to look for the rocking / libration effect, it's not difficult once you know what to look for - there's a small dark 'sea' at about 2 o'clock, near the edge. The appearance of this, (Mare Crisium, the Sea of Crises), changes a lot with libration, as I hope the video shows.

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