The exploration of space by Russia entered a new phase with the first Moon landing by Luna 1 in 1959. In 1960 Russia issued a souvenir sheet which featured a cosmonaut and a lunar vehicle. The stamp on the sheet features images of the three Luna space vehicles and a map of the moon centered at 15°N 120° with North at approximately 11:30. This is the back side, or dark side, or unseen side of the moon.
     The map shows several dark areas. The dark patch at the upper right is Mare Moscoviense at 146°E 25°N. Below and to the left are two larger dark areas. Mare Marginus, “the Sea of the Edge,” and Mare Smythii, named for William Henry Smith (1788-1865), a British Astronomer. At the lower right is the crater Tsilokovskiy, named for Konstantin Tsilkovskiy (1857-1935), a Russian rocket scientist.
     On the right side of the stamp there is a curved line of dashes which marks the “terminator” or edge (generally speaking) of the moon’s visible and hidden sides. A solid line slightly below the middle of the moon, is the moon’s equator.
     A similar map of the hidden side of the moon, based on a photograph taken on October 7, 1959 was issued in 1984 by Bulgaria (C159)