  tranquility base (latin: statio tranquillitatis) is the site where humans first landed on the moon and walked on another world, on the flight of apollo 11. american astronauts neil armstrong and buzz aldrin landed their apollo lunar module eagle at approximately 20:17:40 utc on july 20, 1969. six hours later, they left the spacecraft and spent 2 hours, 31 minutes on the lunar surface, examining and photographing it, setting up some scientific experiment packages, and collecting  of dirt and rock samples for return to earth. they lifted off the surface on july 21 at 17:54 utc. tranquility base has remained unvisited since then. its lunar coordinates are 00Â°41â²15â³n, 23Â°26â²00â³e, in the south-western corner of the lunar lava-plain called mare tranquillitatis ("sea of tranquility"), east of the craters sabine and ritter, north of the crater moltke, and near a rille unofficially called "u.s. highway number 1". ==site selection== for more than two years, nasa planners considered a collection of 30 potential sites for the first manned landing. based on high-resolution photographs taken by the lunar orbiter spacecraft, and photos and data taken by the unmanned surveyor landers, this list was narrowed down to five sites located near the lunar equator, ranging between 45 degrees east and west, and 5 degrees north and south of the center of the moon's facing side; these were numbered 1 to 5 going from east to west. site number 2, centered at {{c
Apollo_program Exploration_of_the_Moon LQ12_quadrangle