Comets are believed to retain most of the original content
 of the pristine Solar Nebula. Therefore, their study
 provides a unique way to understand the history of our Solar
 System and its relation to the interstellar medium.

 We propose to complement the Central Program study of periodic
 comet P/Kopff by observing at high resolution with the SWS
 the 3.20 to 3.65 mu and 5.80 to 7.00 mu regions.

 The primary goal of this proposal is to investigate the nature
 of the carbonaceous components present in cometary atmospheres.
 Comets have a strong emission in the 3.20-3.65 mu domain. Part of
 it is attributed to methanol, but the remaining signal is still
 unidentified.

 A spectrum of the 3.20-3.65 mu region free of any telluric
 absorption will help resolving this problem.

 The 5.80-7.00 mu region has never been observed in comets
 at high resolution (a low resolution spectrum of P/Halley
 revealed an unidentified feature at 6.8 mu). This region
 potentially contains the signals of hydrocarbons, aromatics,
 and CHO species. Its observation will directly complement
 that of the 3.20-3.65 mu and allow to identify cometary
 carbonaceous compounds. In addition, this region contains
 the strong nu2 band of water, whose study at high resolution
 will usefully complement the observations of cometary water
 of the Central Program.