Andrew E. Douglass

Andrew Ellicott Douglass (July 5,1867 – March 20,1962) was an American astronomer.

His most prominent work was actually not in astronomy, but in founding the discipline of dendrochronology, which is a method of dating wood by looking at the growth ring pattern. He started his discoveries in this field in 1894 when he was working at the Lowell Observatory. During this time he was an assistant to Percival Lowell and William Henry Pickering, but had a falling-out with them, when his experiments made him doubt the existence of artificial "canals" on Mars and visible cusps on Venus.

A crater on Mars is named in his honor.