How well do you think you know your own city? Could you recognize it in the dead of night... from space? NASA is hoping to use a wealth of images of Earth taken from the International Space Station to measure light pollution and energy consumption across the globe, and is asking for the help of the world's citizens. (Photo : NASA)

How well do you think you know your own city? Could you recognize it in the dead of night... from space? NASA is hoping to use a wealth of images of Earth taken from the International Space Station to measure light pollution and energy consumption across the globe, and is asking for the help of the world's citizens.

According to the space agency, countless images of Earth have been taken as early as the 1960's. They picture the lights of the world's cities at night, lighting up an otherwise dusky globe. However, it is unclear where a great multitude of the images are picturing. That's where everyday citizens come in.

As part of a crowd sourcing campaign launched by the space agency called "Dark Skies of ISS," NASA is asking people from around the world to help them sort the images into three categories - cities, stars , and other objects. A second campaign called "Night Cities" is asking that people with geographic knowledge help them identify city features that can be used to properly position the ISS photos on a map.

"Anyone can help," Alejandro Sanchez, a Ph.D. student at the Complutense University of Madrid (UCM) said in a recent release. "In fact, without the help of citizens, it is almost impossible to use these images scientifically. Algorithms cannot distinguish between stars, cities, and other objects, such as the moon. Humans are much more efficient for complex image analysis."

A final more complex project called "Lost at Night" is asking that citizens help them identify cities through just pinpricks of light within a 310 mile circle on Earth's surface.

"We don't know which direction the astronaut pointed the camera, only where the station was at the time the image was taken," Sanchez explained. "Some images are bright cities but others are small towns. It is like a puzzle with 300,000 pieces."

The three projects have already classified nearly 20,000 images, but NASA would love more participation. To ensure accuracy, the agency is looking to have each image classified multiple times

NASA hopes to one day use these combined and organized images to make an ultimate atlas of light pollution and efficiency. Such an atlas could clearly show where electricity may be poorly managed, giving city-planners a better too for comparison and perspective.