Two Craters South of Sirenum Fossae
NASA/JPL/University of Arizona
Two Craters South of Sirenum Fossae
ESP_012997_1445  Science Theme: Landscape Evolution
French  Italian  Spanish 

WALLPAPER

800  1024
1152  1280
1440  1600
1920  2048
2560

HIFLYER

PDF, 11 x 17 in
This image shows two craters in the southern hemisphere just south of Sirenum Fossae.

The northern crater is smaller, appears more degraded, and is partially filled with sediments that form a hummocky surface. Dunes have formed subsequently on this surface. Some incipient gully-like features have formed midway along the southern crater wall and expose layers that are more resistant to erosion.

The larger crater to the south is eroded by gullies on its northern slope while the southern slope region lacks them. Most gullies in this scene appear to emanate from more resistant layers, although the larger gullies have eroded back almost to the crater rim.

The nature of the layers and their connection to the water that formed the gullies is unknown. Gullies typically form when flowing water erodes sediments and soft rocks in a channelized flow. Because Mars is very cold and dry, it is unknown where the water came from to form the gullies.

Written by: Kate Coleman & Ginny Gulick  (3 June 2009)
twitter  •  facebook  •  google+  •  tumblr
 
Acquisition date
05 May 2009

Local Mars time:
15:13

Latitude (centered)
-35.043°

Longitude (East)
204.403°

Range to target site
251.3 km (157.1 miles)

Original image scale range
50.3 cm/pixel (with 2 x 2 binning) so objects ~151 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle:
0.6°

Phase angle:
43.3°

Solar incidence angle
43°, with the Sun about 47° above the horizon

Solar longitude
259.8°, Northern Autumn

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  6.1°
JPEG
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

JP2
Black and white
map-projected   (72MB)

IRB color
map-projected   (36MB)

JP2 EXTRAS
Black and white
map-projected  (31MB)
non-map           (44MB)

IRB color
map projected  (8MB)
non-map           (48MB)

Merged IRB
map projected  (77MB)

Merged RGB
map-projected  (70MB)

RGB color
non map           (44MB)
ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products
HiView

NB
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

USAGE POLICY
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/JPL/University of Arizona

POSTSCRIPT
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.