NASA's Deep Space 1 (DS1) spacecraft successfully encountered comet 19P/Borrelly near perihelion on 22 September 2001. The Miniature Integrated Camera and Spectrometer (MICAS) imaging system onboard DS1 returned the first high-resolution images of a Jupiter-family comet nucleus and surrounding environment [1]. Numerous surface features are revealed on the 8-km long nucleus in the highest resolution, stereo images (47-58 m/pixel). A smooth, broad basin containing brighter regions and mesa-like structures is present in the central part of the nucleus and high ridges seen along the jagged terminator lead to rugged terrain on both ends of the very dark nucleus. No impact craters with diameters larger than about 200-m are present and infrared spectra reveal a hot, dry surface consistent with less than 10% actively sublimating. Two types of dust features are seen: broad fans and highly collimated jets that can be traced to the surface. The source region of the main jet, which resolves into at least three smaller jets near the surface, is consistent with an area around the rotation pole that is constantly illuminated during the encounter. The Plasma Experiment for Planetary Exploration (PEPE) instrument returned ion mass spectrometer measurements along the trajectory of DS1 through the coma [2]. Water-group species were observed during the last several minutes about closest approach [3]. The latest results of the DS1 Mission are provided with comparisons to previous comet missions and theoretical models.

[1] Soderblom, L.A. et al. (2002) Science 296, 1087-1091.

[2] Young, D.T. et al. (2002) Science, in press.