Recent picture of the Apollo 12 landing site taken from the Lunar Recon. Orbiter.

At each site, trails also run to the west of the landers, where the astronauts placed the Apollo Lunar Surface Experiments Package (ALSEP) to monitor the moon's environment and interior.

This equipment was a key part of every Apollo mission. It provided the first insights into the moon's internal structure, measurements of the lunar surface pressure and the composition of its atmosphere. Apollo 11 carried a simpler version of the science package.

One of the details that shows up is a bright L-shape in the Apollo 12 image. It marks the locations of cables running from ALSEP's central station to two of its instruments. Although the cables are much too small for direct viewing, they show up because they reflect light very well.

The higher resolution of these images is possible because of adjustments made to LRO's orbit, which is slightly oval-shaped or elliptical. "Without changing the average altitude, we made the orbit more elliptical, so the lowest part of the orbit is on the sunlit side of the moon," said Goddard's John Keller, deputy LRO project scientist. "This put LRO in a perfect position to take these new pictures of the surface."

The maneuver lowered LRO from its usual altitude of approximately 31 miles (50 kilometers) to an altitude that dipped as low as nearly 13 miles (21 kilometers) as it passed over the moon's surface. The spacecraft has remained in this orbit for 28 days, long enough for the moon to completely rotate.