1975 10¢ Mariner 10
Issue Date: April 4, 1975
City: Pasadena, California
Printed By: Bureau of Engraving and Printing
Printing Method: Lithographed, engraved
Color: Black, red, ultramarine, and bister
This stamp commemorates the Mariner 10 space project. Mariner 10 swung within 3,600 miles of Venus in 1974. Afterward, it made the first near examination ever of Mercury, the smallest planet.