by John A. Wood LUNAR SCIENCE Apollo 11 astronaut Buzz Aldrin sets up a seismometer on the Moon. The instrument worked for three weeks, detecting moonquakes and gathering information about the Moon's internal structure. Later missions' seismometers transmitted data until 1977. 14 J U LY 2 0 1 9 * S K Y & T E L E S C O P E N ASA THE MOON: FIRST LUNAR SAMPLES