Isolated Araneiform Topography
Isolated Araneiform Topography
PSP_003087_0930  Science Theme: Seasonal Processes
Have you ever found that to describe something you had to go to the dictionary and search for just the right word?

The south polar terrain is so full of unearthly features that we had to visit Mr. Webster to find a suitable term. “Araneiform” means “spider-like.” These are channels that are carved in the surface by carbon dioxide gas. We do not have this process on Earth.

The channels are somewhat radially organized and widen and deepen as they converge. In the past we’ve just referred to them as “spiders.” “Isolated araneiform topography” means that our features look like spiders that are not in contact with each other.

This caption is part of a December 2007 AGU presentation Spring at the South Pole of Mars.

Written by: Candy Hansen  (12 December 2007)

This is a stereo pair with PSP_003720_0930.
Acquisition date
24 March 2007

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
244.4 km (151.9 miles)

Original image scale range
24.5 cm/pixel (with 1 x 1 binning) so objects ~73 cm across are resolved

Map projected scale
25 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
81°, with the Sun about 9° above the horizon

Solar longitude
206.4°, Northern Autumn

For non-map projected images
North azimuth:  159°
Sub-solar azimuth:  33.7°
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
map projected

RGB color
non-map projected

Black and white
map-projected   (691MB)

IRB color
map-projected   (383MB)

Black and white
map-projected  (406MB)
non-map           (456MB)

IRB color
map projected  (143MB)
non-map           (377MB)

Merged IRB
map projected  (162MB)

Merged RGB
map-projected  (159MB)

RGB color
non map           (321MB)
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

IRB: infrared-red-blue
RGB: red-green-blue
About color products (PDF)

Black & white is 5 km across; enhanced color about 1 km
For scale, use JPEG/JP2 black & white map-projected images

All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible:

NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA’s Science Mission Directorate, Washington. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.