Taken mostly by the International Space Station (ISS), the photos are available in an online collection. Nasa has some 1.8 million images of the earth, including 1.3 million from the ISS.
Called the Image Detective Programme, people are being asked to identify particular towns and landmarks.
Hundreds of volunteers have already classified nearly 20,000 images, but these need to be confirmed by multiple people.
According to Nasa, this could help save energy, contribute to better human health and safety, and improve understanding of atmospheric chemistry.
Nasa's home page for the project is inviting entries:
Haven't you always wanted to associate those amazing photographs of our beautiful planet taken from space with their specific locations on the Earth? With the Image Detective web page, you can do just that! By doing so, you will help to locate hundreds of thousands of images and also enhance your geography skills at the same time. You can gauge how high your skill level is by accumulating points as you submit each image, then checking out the "Who Has High Score?" icon on the front page.
Users can pick identified images and tag them on the amount on cloud cover, and other features they are able to identify.
Nasa is offering rewards to those who identify the most images, in the form of a place in the high-score leaderboard and badges.
Written with inputs from IANS