A HIGH-RESOLUTION ATLAS OF THE SATURNIAN MOON ENCELADUS DERIVED FROM CASSINI IMAGES

T. Roatsch¹, M. Waehlisch¹, B. Giese¹, A. Hoffmeister¹, K.-D. Matz¹, F. Scholten¹, R. Wagner¹, A. Kuhn¹, G. Neukum², G. Helfenstein³, C. Porco⁴

1 - German Aerospace Center

2 - Freie Universitaet Berlin

3 - Cornell University, Ithaca

4 - Space Science Institute, Boulder

marita.waehlisch@dlr.de

The Cassini spacecraft is on tour through the Saturnian system since July 2004. The Imaging Science Subsystem (ISS) onboard the orbiter consists of a high-resolution Narrow Angle Camera and a Wide Angle Camera (Porco et al., 2004). The Cassini ISS acquired 377 images in a resolution better than 1 km/pixel during three close flybys of Enceladus in 2005 [Porco et al., 2006]. We combined these images with lower-resolution Cassini images and two others taken by Voyager cameras during the Voyager mission in the early 1980’s to produce a high-resolution global controlled mosaic of Enceladus with a spatial- resolution of about 110 m/pixel 2005 [Roatsch et al., 2006]. Additionally, we improved pointing data of 11 Narrow Angle Camera images using block adjustment techniques to calculate a medium-resolution, controlled mosaic. We registered the high-resolution mosaic onto the controlled mosaic to improve its global accuracy. The global mosaic is the baseline for a high-resolution Enceladus atlas that consists of 15 tiles mapped at a scale of 1:500,000. The equatorial part of the atlas is in Mercator projection onto a secant cylinder, the regions between the equator region and the poles are projected in Lambert conic projection with two standard parallels and the poles are projected in stereographic projection. We added coordinate grids, resolution maps and index maps for every individual tile, showing the image resolution, the image numbers and the location of the images for every map, respectively. Part of the nomenclature used in this atlas was proposed by the Cassini imaging team and is awaiting validation by the IAU. The atlas will be made available to the public through CICLOPS (http://ciclops.org) and PDS (http://pds.jpl.nasa.gov).

The Cassini spacecraft will continue its imaging campaign through the Saturnian system until the end of the nominal mission in 2008. The new data will be used to further improve the existing mosaics and maps.

Porco, C. C. and 19 co-authors, 2004, Cassini Imaging Science: Instrument Characteristics and Anticipated Scientific Investigations at Saturn, Space Science Review 115, 363-497.

Porco, C. C. and 24 co-authors, 2006, Cassini Observes the Active South Pole of Enceladus, Science 311, 1393-1401.

Roatsch, T., Wählisch M., Scholten, F., Hoffmeister, A., Matz, K. -D., Denk, T., Neukum G. Thomas, P., Helfenstein, P., and Porco, C., 2006, Mapping of the icy Saturnian satellites: First results from Cassini-ISS, Planetary Space Sciences 54, 1137 – 1145.