PIA08423: Low Sun from 'Low Ridge'


Low Sun from ‘Low Ridge’

Caption:

A spectacular field of Martian sand ripples separates NASA's Mars Exploration Rover Spirit from the slopes of "Husband Hill." It has been 200 Martian days, or sols, since the rover started a descent from the top of the peak to the rover's current position on "Low Ridge." Looking back to the north on sol 813 (April 17, 2006), Spirit acquired this blue-filter (436-nanometer) view with the right panoramic camera (Pancam) while the Sun was low in the sky late in the afternoon. Because of the low-angle lighting (sunlight is coming from the left), images like this provide superb views of subtle textures in the topography both near and far. Husband Hill, where the rover was perched late last summer, rises prominently just left of center in this view. A 150-meter wide (500 foot) field of curving sand ripples named "El Dorado" lies at the base of Husband Hill.

By collecting photos like this at different times of day, when lighting comes from different directions, scientists can distinguish surface properties such as color and reflectivity from topography and roughness. By separating these components they can map more details of the geologic terrain, providing new clues about the geologic history of Gusev Crater.

Cataloging Keywords:

Name Value Additional Values
Target Mars
System
Target Type Planet
Mission Mars Exploration Rover (MER)
Instrument Host Spirit (MER-A)
Host Type Rover
Instrument Panoramic Camera (Pancam)
Detector
Extra Keywords Crater, Grayscale, Map
Acquisition Date
Release Date 2006-05-01
Date in Caption 2006-04-17
Image Credit NASA/JPL-Caltech/Cornell
Source photojournal.jpl.nasa.gov/catalog/PIA08423
Identifier PIA08423