Deep Impact as a World Observatory Event: Synergies in Space, Time, and Wavelength

Abstract

We present mid-infrared spectra of the GEMINI-N (+MICHELLE) observations of comet 9P/Tempel 1 during its encounter with Deep Impact (≈7 min cadence). Based on our modeling of the spectra, we find that the submicron sized dust grains travel away from the nucleus faster than the larger grains. Groups of grains of differing mineral composition travel at different ejection velocities. Amorphous olivine and amorphous carbon grains travel together at one speed, while amorphous pyroxene and crystalline olivine travel together at another speed. The different speed of the two mineral groups implies that Deep Impact excavated a layer of material below an amorphous carbon and amorphous olivine rich surface layer to release an amorphous pyroxene and crystalline olivine rich layer. ©2009 Springer-Verlag Berlin Heidelberg.