July is always hot in the Northern Hemisphere, and today will see record temperatures throughout most of North America. The sun, however, is currently about as far from us as it gets in its yearly journey. Peak aphelion occurred this year on July 4, despite what you might believe from the thermometer! The word aphelion was coined by Johannes Kepler, the German mathematician and astronomer, based on converting the Modern Latin word aphelium back to its Ancient Greek origins on the model of Ptolemy’s word apogaeum (see the modern English word apogee) meaning away from the earth. Ptolemy’s word reflected a time when the Earth stood at the center of the planetary and solar system, and not the sun. By extension the word perihelion was formed, also from the Ancient Greek roots: where apo- meant away from peri- meant near, and helion designated the sun. Next time you step outside into the blistering sun, remember that it is about as far away as it gets!
While Kepler is considered the chief proponent of the Copernican system and a leading figure of the astronomical revolution, he died in 1630-and the word aphelion didn’t see common use in English until 1670.
Image courtesy www.mydarksky.org, a very cool site, check it out!