July/August 1991 | Volume 42, Issue 4
On the night of August 25 a tracking station in Madrid received the first transmissions of pictures of the Earth as seen from the moon, 240,000 miles away. A camera mounted on NASA’s lunar orbiter, the first American spacecraft to circle the moon, shot the photographs from 24.7 miles above its surface. The initial pictures showed the Moon in huge, curving profile in the foreground; a smaller Earth dangled behind in space, wrapped completely in clouds. The orbiter moved slightly closer to the Moon to take pictures of craters, in search of possible future landing sites; according to a NASA official, a manned voyage to the moon was expected by the end of the decade.
The photographs were also important to scientists for pinpointing the earth’s terminator line, the line dividing the planet into light and dark halves. The lunar orbiter made a complete circle of the Moon every three and a half hours during its mission, sending back pictures each day; they were too clouded to reveal oceans and continents, but the space station scientists nonetheless pronounced them “beautiful.”