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The distance between the Moon and Earth varies from around 356,400 km (221,500 mi) to 406,700 km (252,700 mi) (apogee), making the Moon's distance and apparent size fluctuate up to 14%. [202] [203] On average the Moon's angular diameter is about 0.52°, roughly the same apparent size as the Sun (see § Eclipses).
(The Sun's diameter is 400 times as large and its distance also; the Sun is 200,000 to 500,000 times as bright as the full Moon (figures vary), corresponding to an angular diameter ratio of 450 to 700, so a celestial body with a diameter of 2.5–4″ and the same brightness per unit solid angle would have the same brightness as the full Moon.)
Then, when the seemingly very large Moon is on the horizon, the same pebble will also cover it, revealing that there has been no change in the size of the Moon. Across different full moons, the Moon's angular diameter can vary from 29.43 arcminutes at apogee to 33.5 arcminutes at perigee —a variation of around 14% in apparent diameter or 30% ...
The largest possible apparent diameter of the Moon is the same 12% larger (as perigee versus apogee distances) than the smallest; the apparent area is 25% more and so is the amount of light it reflects toward Earth. The variance in the Moon's orbital distance corresponds with changes in its tangential and angular speeds, per Kepler's second law.
But this theory, applied to its logical conclusion, would make the distance (and apparent diameter) of the Moon appear to vary by a factor of about 2, which is clearly not seen in reality. [15] (The apparent angular diameter of the Moon does vary monthly, but only over a much narrower range of about 0.49°–0.55°. [16])
Comparison of angular diameter of the Sun, Moon and planets with the International Space Station and human visual acuity, compiled by CMG Lee. To get a true representation of the sizes, view the image at a distance of 103 [1 / tan(33.5/60 * pi/180)] times the width of the largest (Moon: max.) circle.
The angular size redshift relation for a Lambda cosmology, with on the vertical scale megaparsecs. The angular size redshift relation describes the relation between the angular size observed on the sky of an object of given physical size, and the object's redshift from Earth (which is related to its distance, , from Earth
Comparison of angular diameter of some celestial bodies: Image title: Comparison of angular diameter of the Sun, Moon and planets, compiled by CMG Lee. To get a true representation of the sizes, view the image at a distance of 103 [1 / tan(33.5/60 * pi/180)] times the width of the largest (Moon: max.) circle.