Скачать или смотреть An animated diagram of the subsolar and sub-Earth points for 2021.

The subsolar and sub-Earth points are the locations on the Moon's surface where the Sun or the Earth are directly overhead, at the zenith. A line pointing straight up at one of these points will be pointing toward the Sun or the Earth. The sub-Earth point is also the apparent center of the Moon's disk as observed from the Earth.

In the animation, the blue dot is the sub-Earth point, and the yellow cone is the subsolar point. The lunar latitude and longitude of the sub-Earth point is a measure of the Moon's libration. For example, when the blue dot moves to the left of the meridian (the line at 0 degrees longitude), an extra bit of the Moon's eastern limb is rotating into view, and when it moves above the equator, a bit of the far side beyond the south pole becomes visible.

At any given time, half of the Moon is in sunlight, and the subsolar point is in the center of the lit half. Full Moon occurs when the subsolar point is near the center of the Moon's disk. When the subsolar point is somewhere on the far side of the Moon, observers on Earth see a crescent phase.

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