Observations of Comet 19P/Borrelly by the Miniature Integrated Camera and Spectrometer Aboard Deep Space 1

Soderblom, L. A.
Becker, T. L.
Bennett, G.
Boice, D. C.
Britt, D. T.
Brown, R. H.
Buratti, B. J.
Isbell, C.
Giese, B.
Hare, T.
Hicks, M. D.
Howington-Kraus, E.
Kirk, R. L.
Lee, M.
Nelson, R. M.
Oberst, J.
Owen, T. C.
Rayman, M. D.
Sandel, B. R.
Stern, S. A.
Thomas, N.
Yelle, R. V.

¹United States Geological Survey, 2255 North Gemini Drive, Flagstaff, AZ 86001, USA. ²Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA. ³Department of Geological Sciences, University of Tennessee, 306 Geological Sciences Building, Knoxville, TN 37996, USA. ⁴Department of Planetary Science, Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA. ⁵Jet Propulsion Laboratory (JPL), California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. ⁶DLR Institute of Space Sensor Technology and Planetary Exploration, Rutherfordstrasse, 2D-12489 Berlin, Germany. ⁷Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA. ⁸Department of Space Studies, Southwest Research Institute, 1050 Walnut Street No. 426, Boulder, CO 80302, USA. ⁹Max-Planck-Institut für Aeronomie, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau, Germany.

*To whom correspondence should be addressed. E-mail: [email protected]

3 January 2002; accepted 26 March 2002

Published online 4 April 2002; 10.1126/science.1069527

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Science 296(5570):p 1087-1091, May 10, 2002.

The nucleus of the Jupiter-family comet 19P/Borrelly was closely observed by the Miniature Integrated Camera and Spectrometer aboard the Deep Space 1 spacecraft on 22 September 2001. The 8-kilometer-long body is highly variegated on a scale of 200 meters, exhibiting large albedo variations (0.01 to 0.03) and complex geologic relationships. Short-wavelength infrared spectra (1.3 to 2.6 micrometers) show a slope toward the red and a hot, dry surface (≤345 kelvin, with no trace of water ice or hydrated minerals), consistent with ∼10% or less of the surface actively sublimating. Borrelly's coma exhibits two types of dust features: fans and highly collimated jets. At encounter, the near-nucleus coma was dominated by a prominent dust jet that resolved into at least three smaller jets emanating from a broad basin in the middle of the nucleus. Because the major dust jet remained fixed in orientation, it is evidently aligned near the rotation axis of the nucleus.