On this day in 1974, Mariner 10, the U.S. space probe became the
first spacecraft to reach the planet Mercury. It had been launched
on November 3, 1973. Mariner 10 was the first spacecraft to return
high-resolution digital color images.

A photomosaic of Mercury images taken by Mariner 10, tinted to approximate the appearance of Mercury.

SANDY KOZEL

In the U.S. on this day in 1951, Julius and Ethel Rosenberg were convicted of conspiracy to commit espionage. They were executed
on June 19, 1953.

On this day in 1971, Lt. William Calley Jr., of the U.S. Army, was
found guilty of the premeditated murder of at least 22 Vietnamese civilians. He was sentenced to life imprisonment. The trial was the
result of the My Lai massacre in Vietnam on March 16, 1968.

The last U.S. troops left South Vietnam on this day in 1973.

It was on this day in 2005.

From left: O.J. Simpson and his attorney Johnnie Cochran.