Neil Armstrong made history when he stepped out onto the Moon's surface on July 21, 1969.  Joined shortly after by Buzz Aldrin, the astronauts had several tasks to carry out in the little over two hours they had on the Moon's surface. One of the Apollo 11 crew's primary tasks was collecting soil and rock samples.  In all, they collected about 50 pounds of rocks and 13 pounds of soil.  Upon returning the rocks to Earth, it was discovered that they had found three new minerals, one of which was named after the three Apollo 11 astronauts (Armalcolite). Armstrong and Aldrin then positioned a device to measure the contents of the solar wind that blew across the Moon.  They also set up equipment to reflect laser beams from Earth, to help determine the exact distance between the Earth and the Moon.  Finally, they placed a passive seismometer to measure moonquakes and meteor crashes.  The most challenging of their tasts was planting the flag, because of the hard rock surface. While Armstrong and Aldrin carried out their tasks, Michael Collins orbited the Moon.  He performed maintenance work and prepared for their return.  They were reunited on July 21 and splashed down in teh Pacific on July 24.  Upon their return, President Nixon greeted them, saying, "As a result of what you've done, the world has never been closer together before."