Olympic Views: The Night Sky from Rio

From now through Aug. 21, the eyes of the world are on Rio de Janeiro, Brazil and the Games of the XXXI Olympiad. If you were a discus thrower living in Athens, Greece, where the latitude is 38 degrees north, Polaris (the North Star) appears 38 degrees or almost halfway up from the northern horizon to the point overhead, called the zenith. As you travel south, Polaris approaches the horizon at the rate of about 1 degree, which is twice the apparent width of the full moon, for every 70 miles