NASA's Lunar Reconnaissance Orbiter has snapped the best images yet of three Apollo landing sites, illustrating the exploration of moon-walking astronauts with views of preserved footpaths and rover tracks on the dull charcoal-colored lunar soil.

NASA's Lunar Reconnaissance Orbiter captured this view of the Apollo 12 landing site. Credit: NASA/Goddard Space Flight Center/ASU
 
Now in its third year circling the moon, LRO captured the landing site imagery from an exceptionally low orbit passing as close as 13 miles above the lunar surface.

Check out more images from LRO.

Previous images from the Lunar Reconnaissance Orbiter Camera from an altitude of 31 miles were fuzzier and didn't show as much detail as the new photos. NASA released imagery of the Apollo 12, 14 and 17 landing sites Tuesday.

"The new low-altitude Narrow Angle Camera images sharpen our view of the moon's surface," said Arizona State University researcher Mark Robinson, principal investigator for the Lunar Reconnaissance Orbiter Camera. "A great example is the sharpness of the rover tracks at the Apollo 17 site. In previous images the rover tracks were visible, but now they are sharp parallel lines on the surface."

Ground controllers maneuvered LRO into an oval-shaped orbit approaching within 13 miles of the moon, where it stayed for 28 days, or a full lunar cycle. The orbit allowed the spacecraft's primary camera to cover the entire lunar surface in four weeks.

NASA was planning to return LRO to its normal 31-mile-high orbit Tuesday.

LRO launched to the moon in June 2009, reached lunar orbit four days later and began a one-year mission mapping potential landing sites for future human voyages. Control of the SUV-sized spacecraft transitioned from NASA's human exploration directorate to the agency's science division last year.

NASA released the first LRO images of Apollo landing sites in July 2009, less than a month after the satellite arrived at the moon.

The tracks from lunar rovers, which astronauts used on the final three landing missions, were barely perceptible in the grainy pictures initially taken by LRO. But the fresh close-up images clearly show footprints, including the last steps taken on the moon during the Apollo 17 mission in December 1972.

"We can retrace the astronauts' steps with greater clarity to see where they took lunar samples," said Noah Petro, a lunar geologist at NASA's Goddard Space Flight Center.

In addition to evidence of heavy foot traffic near the lunar modules, the imagery shows footpaths extending to the west of the landers where astronauts deployed packages of surface experiments to collect data on the moon's environment and interior.