F. Marchis, R. Prangé, J. Christou.

November 1999

The images, taken on 2 consecutive nights (1996/10/21 and 22) at the ESO 3.6m telescope with the ADONIS adaptive optics system equipped with the thermal camera COMIC (2.4-5 microns) display both faces of Io in L' band. Although Io is in daylight, the emission  is dominated by thermal emission  from the hot spots. Use of the IDAC myopic deconvolution method results in a final spatial resolution of about 0.1'' (380 km on Io's surface).
Both faces differ in peak intensity and number of hot spots (left panels). On the middle panels we have superimposed a grid of coordinates (blue) and the location of the hot spots (green) detected by Galileo/NIMS instrument (orbit G1-E4) from Lopes-Gautier et al. (GRL, 1997) with error bars of +/- 3 to 7 degrees. On the Loki face, use of the whole dynamical range illustrates the resolution capabilities. On the right, labelled maps from BDL  (Bureau des Longitudes - Paris) indicate the known hot spots.Bright emissions from the ADONIS images correspond to the "ring of fire" (top) and to Loki and Pele-Pillan (bottom). The saturated Loki image may indicate the presence of new hot spots near north-east limb, in a region not yet observed by NIMS, and near the south pole.

Click on the image for magnification.