ABOUTVAL.TXT

This is a brief text file describing the JPG images of the Mariner Valley.
Note that these image are only available in JPEG format (Though a few of the
images are also in the NASA Gifs file area).

These images cover the area on Mars from a latude of 5 degrees south to 20
degrees south, and a longitude of 35 degrees to 100 degrees. Each image is
about 1250 pixels square, (varying slightly with Latitude). The file name
show the actual location of the centre of the image, (Lat then Long).

The images are all grayscale, and taken from processed VIKING data. For more
info on the Viking mission, see Starbase One's text database, or the SPACE
download area.

Each pixel in the image represents 1/256th of a degree on the surface of Mars.

The Mariner Valley is one of the most spectacular features in the solar system,
being more than 4 times deeper, 6 times wider and 10 times as long as the well
known Grand Canyon of Arizona. The total length is 1/4 of the circumference
of the planet. It features intriguing evidence that there were once very large
volumes of water on Mars.

Users interested in the main sections of the chasm should note that it runs
from about 5S 90 lat to 18S 55 lat. Images of the surrounding terrain are
included in these images.

JPEG viewers/decoders are avaible in the various machine specific graphics
file areas on this board.

A gazetteer of Martian features suitable for loading into a spreadsheet or
database is included in this file area.