A U.S. spaceship early this month raced just 125 miles above the planet closest to the sun, Mercury, and came away with a treasure trove of 1,200 pictures.

The fleet-footed photographer is the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft, or MESSENGER, spacecraft.

It snapped closeup pictures of most of the remaining unseen side of Mercury, a blistering hot planet, and gathered other data as well.

This was the second of three flybys that MESSENGER will make, skimming near the planet that is pockmarked with craters, and this close encounter with the planet has given MESSENGER a kick from Mercurial gravitational pull that will help the spacecraft on its journey, which will help it to orbit Mercury beginning in March 2011.

NASA experts have been enthralled with the pictures that MESSENGER has transmitted back to Earth.

For example, a snapshot shows Mercury about 90 minutes after the spacecraft’s closest approach, clearly imaging a bright crater called Kuiper.

NASA has photographed the crater before, but it has been a while, and the earlier picture wasn’t nearly as high quality. That prior picture was taken by the Mariner 10 mission in the 1970s.

The new pics show that for most of the terrain east of Kuiper, toward the limb (edge) of the planet, the departing images are the first spacecraft views of that portion of Mercury’s surface.

A striking characteristic of this newly imaged area is the large pattern of rays that extend from the northern region of Mercury to regions south of Kuiper.