KECK INFRARED OBSERVATIONS OF SATURNS E-RING AND G-RING DURING EARTHS1995 RING PLANE CROSSINGS

We report the first ground-based detection of Saturn's G ring, togethe r with the first infrared images of the E ring, The data were taken du ring the May and August 1995 ring plane crossings using the W. M. Keck telescope at a wavelength of 2.26 mu m. The E ring's radial and verti cal structure is found to be generally consistent with previous result s from Voyager and Earth-based observatories; it has a brightness peak near the orbit of Enceladus and extends outward to similar to 6 R(s) (Saturn radii), The E ring is similar to 40% fainter at 2.26 mu m than in the visual, confirming and extending previous reports that it is v ery blue in color, The G ring is located at 2.8 R(s) and is unresolved in vertical thickness, Its reflected intensity is similar to that fou nd in the comparable Voyager image, implying that the ring is neutral in color from the visual to the infrared. (C) 1996 Academic Press, Inc .