Infrared spectroscopy is a powerful tool to study the chemical composition of comets and, thus, to derive information about formation and evolution mechanisms and on the materials from which they originated. The Infrared Space Observatory (ISO) has represented a unique facility to observe infrared sources - and comets in particular - in a wide spectral range and under conditions not achievable by ground-based telescopes (for a description of the ISO mission see Kessler et al., 1996). Thanks to ISO it has been possible to evidence typical gas and dust features, whose identification has allowed us to shed light on chemical and structural properties of components present in comets (e.g. Crovisier et al., 1997; 1999a; 1999b).
Within the ISO observational programs called EXTRACT (EXtended Remote Analysis of Coma and Trails) our team has performed both ISOCAM and ISOPHOT observations of the short period comet 103P/Hartley 2, an Edgeworth-Kuiper belt object. The combination of observations by ISO instruments for comets pertaining to the Jupiter family was aimed at gaining information on dynamics and morphology of solid particles distributed in the coma and in the trails and about the chemical properties of gas and dust ejected from the nucleus. In the present paper we report the results of the spectroscopic observations by ISOPHOT.
© European Southern Observatory (ESO) 1999
Online publication: March 1, 1999