The Great Square of Pegasus, an asterism that forms the best-known part of Pegasus the Flying Horse, makes its round of the sky once a day. Bob King
We rarely think about it, but the constellations make one complete cycle of the sky every single day. If you look high in the southern sky around 7 p.m. local time tonight you’ll see the Great Square of Pegasus. 10 hours later, the figure sets in the west but shines brightly for skywatchers around the backside of the Earth where it’s still night. Around 1 p.m., Pegasus rises in the eastern sky in full daylight and then returns to view at nightfall high above our heads.
In antiquity most people assumed the sun and planets revolved around the Earth — the geocentric model — because that what it looked like when you looked up into the sky. Now we know that all the planets orbit the sun in the heliocentric model. Niko Lang
Round and round it goes along with the rest of the constellations, planets, moon and the sun — all caused by the Earth’s spin on its axis. Love may make the world go round, but the rotating Earth makes ...