On this day in 1964, Ranger 7 sent back the first close-up photographs of the moon, with images 1,000 times clearer than anything ever seen from earth-bound telescopes.
On this day in 1991, the United States and Soviet Union both signed the START I Strategic Arms Reduction Treaty, the first to reduce both countries' stockpiles.
On this day in 2011, top-ranked Taiwanese golfer Yani Tseng won the Women's British Open to rack up her fifth major title at the age of 22, an achievement unparalleled by any golfer before her.
And on this day in 2012, Michael Phelps broke the record set in 1964 by Larisa Latynina for the most medals won at the Olympics.