Eugene A. Cernan, Apollo 17 Commander, salutes the flag on the lunar surface during extravehicular activity (EVA) on NASA's final lunar landing mission. The Lunar Module "Challenger" is in the left background behind the flag and the Lunar Roving Vehicle (LRV) also in background behind him. While astronauts Cernan and Schmitt descended in the Challenger to explore the Taurus-Littrow region of the Moon, astronaut Ronald E. Evans, Command Module pilot, remained with the Command/Service Module (CSM) "America" in lunar-orbit. NASA
Astronaut Eugene A. Cernan makes a short checkout of the Lunar Roving Vehicle during the early part of the first Apollo 17 extravehicular activity at the Taurus-Littrow landing site. This view of the "stripped down" Rover is prior to loadup. This photograph was taken by Geologist-Astronaut Harrison H. Schmitt, Lunar Module pilot. The mountain in the right background is the East end of South Massif. NASA
Geologist-Astronaut Harrison Schmitt, Apollo 17 Lunar Module pilot, is photographed next to the American Flag during extravehicular activity (EVA) of NASA's final lunar landing mission in the Apollo series. The photo was taken at the Taurus-Littrow landing site. Earth appears above the flag in the distant background. NASA
Geologist-Astronaut Harrison Schmitt, Apollo 17 lunar module pilot, uses an adjustable sampling scoop to retrieve lunar samples during the second extravehicular activity, at Station 5 at the Taurus- Littrow landing site. The cohesive nature of the lunar soil is born out by the "dirty" appearance of Schmitt's space suit. NASA
Alan L. Bean, Lunar Module pilot for the Apollo 12 mission, starts down the ladder of the Lunar Module 'Intrepid' to join astronaut Charles Conrad, Jr., mission Commander, on the lunar surface. NASA
This composite photo shows President Richard M. Nixon as he telephoned 'Tranquility Base' and astronauts Neil Armstrong and Edwin 'Buzz' Aldrin. The President: "... For one priceless moment in the history of man, all of the people on this Earth are truly one, one in their pride in what you have done and one in our prayers that you will return safely to Earth." Astronaut Armstrong: "...Thank You, Mr. President. It is a great honor and privilege for us to be here representing not only the United States, but men of peaceable nations, men with an interest and curiosity, and men with a vision for the future. It is an honor for us to be able to participate here today. NASA
One of the first steps taken on the Moon, this is an image of Buzz Aldrin's bootprint from the Apollo 11 mission. Neil Armstrong and Buzz Aldrin walked on the Moon on July 20, 1969. NASA
A front view of the Apollo 14 Lunar Module 'Antares,' which reflects a circular flare caused by the brilliant sun. The unusual ball of light was said by the astronauts to have a jewel-like appearance. At extreme left, the lower slope of Cone Crater can be seen. NASA
Apollo 13 astronauts James A. Lovell and Fred W. Haise, Jr., during practice moonwalk at Kennedy Space Center. Lovell (r.) operates Lunar Equipment conveyor, a pulley arrangement to load and unload equipment from the cabin section of Lunar Module. NASA
The Lunar Roving Vehicle is photographed alone against the lunar background during the Apollo 15 lunar surface extravehicular activity at the Hadley-Apennine landing site. This view is looking north. NASA
One Moscow TV station has video that reportedly shows Nemtsov and a woman walking across a bridge shortly before he was killed.
ByLaura Mills, Associated Press
The investigation into the killing of Boris Nemtsov, a fierce critic of Russian President Vladimir Putin who was gunned down not far from the Kremlin, faced conflicting reports Monday about possible surveillance footage of his slaying.