PIA15434: Explosive Allegations

Explosive Allegations


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.

Date acquired: September 07, 2011
Image Mission Elapsed Time (MET): 223922395
Image ID: 730933
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -57.84°
Center Longitude: 329.6° E
Resolution: 193 meters/pixel
Scale: Hesiod crater is about 100 km (62 miles) in diameter
Incidence Angle: 62.7°
Emission Angle: 21.7°
Phase Angle: 84.5°

Background Info:

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.

These images are from MESSENGER, a NASA Discovery mission to conduct the first orbital study of the innermost planet, Mercury. For information regarding the use of images, see the MESSENGER image use policy .

Cataloging Keywords:

Name Value Additional Values
Target Mercury
Target Type Planet
Instrument Host MESSENGER
Host Type Orbiter
Instrument Mercury Dual Imaging System (MDIS)
Detector Narrow Angle Camera (NAC)
Extra Keywords Crater, Grayscale, Map, Radio, Shadow, Volcano
Acquisition Date
Release Date 2012-02-29
Date in Caption 2011-09-07
Image Credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Source photojournal.jpl.nasa.gov/catalog/PIA15434
Identifier PIA15434