Latest revision as of 00:05, 1 August 2015

40 Years Since Impact

Originally published July 31, 2004

40 Years Since Impact

Forty years ago today, the US lunar exploration program finally found success. After a series of embarassing failures, the rocket, the navigation and the cameras all worked, and Ranger 7 radioed back to Earth about 4000 images of ever increasing resolution as it approached and finally slammed into the Moon. I remember being proud when I heard Gerard Kuiper (the Ranger Project Scientist and my boss at the Lunar & Planetary Lab) say on national radio, "It is a great day for America and a great day for science." This is the first picture of the Moon - or any other extraterrestrial world - taken by an American spacecraft. It shows Arzachel, Alphonsus and Ptolemaeus near the sunset terminator, and across Mare Nubium to a line of ruined craters including Guericke, and off the image Fra Mauro. Ranger 7 hit the lunar surface in a patch of mare between Fra Mauro, the Riphaeus Mts and Darney. In honor of this first success in providing high resolution images of the Moon, the International Astronomical Union agreed to name this mare patch Mare Cognitum - the Known Sea. And after Kuiper's death in 1973, a small crater near the middle of Cognitum was given his name.