PIA19232: Riddle Me This

Riddle Me This


This view shows two craters in an area of smooth plains. The crater on the left presents an interesting geological puzzle. Note that about 90° of the rim (in the east, the right side) is sharp. But the remaining 270° of the circumference consists of a broad terrace, formed by slumping and inward movement of material. Why do you think that part of the rim and wall suffered slumping? Differences in the strength of the target material? (And, if so, caused by what?) The angle at which the impactor struck the surface? The topography of the surface? The presence of buried topography or structures? Local or regional tectonics? What additional data could help to solve this riddle?

This image was acquired as a targeted set of stereo images. Targeted stereo observations are acquired at resolutions much higher than that of the 200-meter/pixel stereo base map. These targets acquired with the NAC enable the detailed topography of Mercury's surface to be determined for a local area of interest.

Date acquired: January 19, 2014
Image Mission Elapsed Time (MET): 32450033
Image ID: 5600811
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 32.99°
Center Longitude: 3.36° E
Resolution: 31 meters/pixel
Scale: The crater on the left is about 13 km (8 mi.) in diameter
Incidence Angle: 33.4°
Emission Angle: 3.5°
Phase Angle: 35.9°
North is up in this image.

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. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015.

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, Impact, Map, Radio
Acquisition Date
Release Date 2015-03-09
Date in Caption 2014-01-19
Image Credit NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Source photojournal.jpl.nasa.gov/catalog/PIA19232
Identifier PIA19232