November 8, 1997
On your birthday, the Earth completed another orbit — 584 million miles traveled since your last celebration.
Aristarchus' Unbelievable Discoveries
Birthday · November 8, 1997
A little universe, just for you
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APOD published November 8, 1997. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
Here lived one of the greatest thinkers in human history. Aristarchus lived on the Greek island of Samos, a small island in the center of the above picture that can be identified with a good map. Aristarchus, who lived from 310 BC to 230 BC, postulated that the planets orbited the Sun - not the Earth -- over a thousand years before Copernicus and Galileo made similar arguments. Aristarchus used clear logic to estimate the size of the Earth, the size and distance to our Moon, the size and distance to our Sun, then he even deduced that the points of light we see at night are not dots painted on some celestial sphere but stars like our Sun at enormous distances. Aristarchus' discoveries remained truly unbelievable to the people of his time but stand today as pillars of deductive reasoning.