September 07, 2011
Image Mission Elapsed Time (MET):
Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Hesiod crater is about 100 km (62 miles) in diameter
The crater at the western corner of this image is Hesiod. The northern and eastern parts of Hesiod's rim are marked by irregular depressions. These depressions
are thought to be vents from which explosive (pyroclastic) volcanic eruptions originated.
The high-reflectance areas on the wall of the crater just to the northeast of Hesiod and at the top of the image share color characteristics with other pyroclastic deposits
known on Mercury. Pyroclastic eruptions are driven by volatile compounds, and MESSENGER has revealed that Mercury has a higher abundance of volatile elements
than was previously expected.
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 addressing. During the one-year primary mission, MDIS is scheduled to acquire more than 75,000 images in support of MESSENGER's science goals.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
For information regarding the use of MESSENGER images, see the image use policy.