NASA has used four years worth of camera data from its Lunar Reconnaissance Orbiter (LRO) to stitch together a massive mosaic image of the Moon's north pole.

The high-resolution image - nearly 867 billion pixels total - covers an area equal to more than one quarter of the United States.

Click here to access the image in full resolution. Users can zoom in and out and pan around the lunar north pole.

The mosaic is constructed from 10,581 pictures, providing enough detail so that the subtle shading of the lunar terrain can be observed.

"This unique image is a tremendous resource for scientists and the public alike," said John Keller, LRO project scientist at NASA's Goddard Space Flight Center, Greenbelt, Md. "It's the latest example of the exciting insights and data products LRO has been providing for nearly five years."

The LRO has an instrument suite known as the Lunar Reconnaissance Orbiter Camera (LROC), and two narrow-angle camera on the LROC were used to take the mosaic images.

"Creation of this giant mosaic took four years and a huge team effort across the LRO project," said Mark Robinson, principal investigator for the LROC at Arizona State University. "We now have a nearly uniform map to unravel key science questions and find the best landing spots for future exploration."

The entire image is at such a high resolution that if it were to be printed out at the magazine industry standard of 300 dots per inch, it would require a square sheet of paper wider than a US professional football field and almost as long, NASA said in a statement.

If the image were compressed as a single file, it would require 3.3 terabytes of storage space, NASA said.

The LRO entered orbit around the Moon in June 2009 to map the lunar surface, "probe the radiation environment, investigate water and key mineral resources, and gather geological clues about the moon's evolution," NASA said.