Messenger Offers a Stunning Peek at Cratered Mercury

March 29, 2011: NASA's Messenger spacecraft -- the first ever to orbit the innermost planet -- offers up its first fresh glimpse of Mercury. The dominant rayed crater in the upper portion of the image is Debussy. The smaller crater Matabei with its unusual dark rays is visible to the west of Debussy. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

On March 17, Messenger became the first spacecraft to orbit the planet Mercury. In the course of the $446 million probe's one-year primary mission, the spacecraft's seven scientific instruments and radio science investigation will unravel the history and evolution of the Solar System's innermost planet. (NASA)

March 29, 2011: Messenger captures a never-before-seen area of Mercury’s surface -- taken from just 280 miles above the planet during the spacecraft’s first orbit with the camera in operation. The area is covered in secondary craters made by an impact outside of the field of view. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

March 29, 2011: Bright rays, consisting of material ejected on impact and secondary craters, spread across this image and radiate from the Debussy crater, located at the top. The photo, taken Tuesday during Messenger's first orbit, shows just a small portion of Debussy's large system of rays in greater detail than ever previously seen. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

March 29, 2011: Messenger's wide-angle camera, which took this picture, is not a typical color camera. It can image in 11 colors, ranging from 430 to 1020 nm wavelength (visible through near-infrared). Here, several craters are shown; the bright rays of Hokusai crater to the north cross the image. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

An artist's concept shows the Messenger spacecraft approaching Mercury. In 2008, Messenger successfully flew by the planet and used its gravity to alter the probe’s path. This put it on track to become, in March 2011, the first spacecraft ever to orbit the innermost planet in the solar system. (NASA)

Oct. 7, 2008: Messenger shot this image about 89 minutes before the craft’s closest approach to Mercury in 2008. 

Messenger captured this close-up image of a portion of Mercury’s surface on Oct. 6, 2008 -- mere minutes before its closest approach. The features in the foreground, near the right side of the image, are close to the "terminator," the line between the sunlit dayside and dark night side of the planet. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

Oct. 6, 2008: Machaut crater (named for a medieval French poet and composer), approximately 60 miles in diameter, was first seen under high-sun conditions by the Mariner 10 spacecraft in the 1970s. This image shows an amazing new view of Machaut taken during Messenger’s second flyby of Mercury.