WASHINGTON - JULY 20: (L-R) Astronauts, Walt Cunningham, Apollo 7, James Lovell, Apollo 8 and Apollo 13, David Scott, Apollo 9 and Apollo 15, Buzz Aldrin, Apollo 11, Charles Duke, Apollo 16, Thomas Stafford, Apollo 10 and Eugene Cernan, Apollo 10 and Apollo 17, participate in a news conference at NASA Headquarters on July 20, 2009 in Washington, DC. Today marks the fortieth anniversary of the first moon landing and moon on walk by astronauts Neil Armstrong and Buzz Aldrin which took place on July 20, 1969.