PIA07575: Tirawa at Twilight

Tirawa at Twilight


The giant Tirawa impact basin straddles the day and night boundary on Saturn's moon Rhea in this view from the Cassini spacecraft. The ancient basin is 5 kilometers (3 miles) deep in places, as measured in NASA Voyager images. The basin is 360 kilometers (220 miles) across.

The prominent bright splotch to the southeast of Tirawa is ejecta from a fairly fresh crater. This feature can be seen at much higher resolution in PIA06648 . This view of Rhea (1,528 kilometers, or 949 miles across) reveals terrain slightly to the east of a similar Cassini view, released earlier (see PIA07539 ). The sunlit surface in this view is principally on the leading hemisphere of Rhea. North is up and rotated 13 degrees to the left.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 13, 2005, at a distance of approximately 2 million kilometers (1.2 million miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 50 degrees. Resolution in the original image was 12 kilometers (7 miles) per pixel. The image has been contrast-enhanced and magnified by a factor of two to aid visibility.

Background Info:

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . For additional images visit the Cassini imaging team homepage http://ciclops.org .

Cataloging Keywords:

Name Value Additional Values
Target Rhea Saturn, Sun
System Saturn
Target Type Satellite Planet, Sun
Mission Cassini-Huygens Voyager
Instrument Host Cassini Orbiter
Host Type Orbiter Flyby Spacecraft
Instrument Imaging Science Subsystem (ISS)
Detector Narrow Angle Camera
Extra Keywords Crater, Grayscale, Visual
Acquisition Date
Release Date 2005-08-30
Date in Caption 2005-08-13
Image Credit NASA/JPL/Space Science Institute
Source photojournal.jpl.nasa.gov/catalog/PIA07575
Identifier PIA07575