Hilly Terrain NW of Angkor Vallis

With the Sun low on the horizon, shadows accentuate the hilly nature of this terrain. This surface has been battered by repeated impacts for billions of years, creating the hilly surface that exists today. As a previous featured image of a nearby area put it, Mercury has been a "planetary punching bag."

This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week.

Date acquired: November 12, 2013
Image Mission Elapsed Time (MET): 26543484
Image ID: 5181047
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 67.11°
Center Longitude: 249.8° E
Resolution: 11 meters/pixel
Scale: This image is 14.6 kilometers (9.1 miles) across
Incidence Angle: 82.0°
Emission Angle: 36.9°
Phase Angle: 118.9°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Note: This image is located northwest of Angkor Vallis in the Raditladi Quadrangle.

Angkor Vallis

On April 30, 2013 the International Astronomical Union (IAU) Working Group for Planetary System Nomenclature approved new names for five broad valleys on Mercury (Angkor Vallis). These valleys have been interpreted by MESSENGER team scientists as having formed due to mechanical and thermal erosion of Mercury's surface by hot, low-viscosity, quickly-flowing lavas.

Each image this week will feature one of these five broad valleys, now termed "valles" (sing. "vallis") by the IAU. The valleys are named according to the theme of "abandoned cities (and towns and settlements) of antiquity" that was developed especially for these landforms.

The vallis shown in this figure is named for Angkor city in Cambodia, the largest pre-industrial city in the world, and once the seat of the Khmer Empire. At its peak, Angkor hosted over 1,000 temples, including the world's largest religious monument. With a suburban footprint of ca. 1,000 km², Angkor at one time may have had a population of over 1 million people. This image is a portion of the MDIS global mosaic basemap that was acquired during MESSENGER's first year in orbit.

Date Created: March 26, 2013
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Feature Latitude Range: 56.2° N to 58.4° N
Feature Longitude Range: 112.7° E to 115.6° E
Feature Diameter: 95 km
Resolution: 250 meters/pixel
Projection: Azimuthal equidistant

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

New Names for Five Mercurian Valles

From the USGS Astrogeology Science Center:

The Working Group for Planetary System Nomenclature has approved new names for five valles on Mercury: Angkor Vallis, Cahokia Vallis, Caral Vallis, Paestum Vallis, and Timgad Vallis. For more information, see the Gazetteer of Planetary Nomenclature.