This image shows a double ring impact basin with a smaller,
younger crater superimposed on its rim. Larger impacts, such as
the one that created this basin, form ring structures instead of
central peaks. This image was acquired as part of MDIS's high-
resolution surface morphology base map. The surface morphology
base map will cover more than 90% of Mercury's surface with an
average resolution of 250 meters/pixel (0.16 miles/pixel or 820
feet/pixel). Images acquired for the surface morphology base map
typically have off-vertical Sun angles (i.e., high incidence
angles) and visible shadows so as to reveal clearly the
topographic form of geologic features. The MESSENGER spacecraft
is the first ever to orbit the planet Mercury, and the
spacecraft's seven scientific instruments and radio science
investigation are unraveling the history and evolution of the
Solar System's innermost planet. Visit the Why Mercury? section
of this website to learn more about the key science questions
that the MESSENGER mission is addr