Happy equinox! It was today at 14:49 UTC. So here's a photo of our equinoctal and solsticial planet.
One of the most frequently misunderstood concepts in science is the reason for Earth’s seasons. As we experience the September equinox today—anyone try to balance an egg yet? —we thought we’d offer a space-based view of what’s going on. Around 6 a.m. local time each day, the Sun, Earth, and any geosynchronous satellite form a right angle, affording a nadir (straight down) view of the terminator, the edge between the shadows of nightfall and the sunlight of dusk and dawn. The shape of this line between night and day varies with the seasons, which means different lengths of days and differing amounts of warming sunshine. (The line is actually a curve because the Earth is round, but satellite images only show it in two-dimensions.) The Spinning Enhanced Visible and Infrared Imager (SEVIRI) on EUMETSAT's Meteosat-9 captured these four views of Earth from geosynchronous orbit. ...