It was a big week at Nasa this week. The space shuttle Discovery rolled into its autumn years, retiring to the US National Air and Space Museum after one last flight atop a specially designed shuttle carrier craft.
Discovery completed 39 missions, spending 365 days in space. It orbited Earth 5,830 times and traveled 148,221,675 miles during its lifespan.
Some of Nasa's most magnificent shots are of cities on Earth shot from the international space station at night.
Moscow is shown in a nighttime photo by a member of the Expedition 30 crew aboard the ISS on March 28, 2012. If you like that, you'll probably enjoy the magnificent shot of greater London shot from the ISS too.
The tech you see at the left of the shot is a solar array panel which helps to power the floating workplace. You can also see the Aurora Borealis and the sunrise sneaking over the horizon.
Click through the slideshow below for this week's top Nasa photos.