Dr. Carey Lisse Johns Hopkins University -Applied Physics Laboratory

1. Deep Impact & Spitzer : A Rosetta Stone for Comets and Asteroids in the Solar System and Around Other Stars Dr. Carey Lisse Johns Hopkins University -Applied Physics Laboratory

2. Summary • We have a new tool from the Deep Impact experiment, that allows us to understand the makeup of comets and asteroids, and to understand where and when comets and asteroids formed and evolved. • We have now successfully applied the tool to the ‘gold standard’ of comet studies, Comet Hale-Bopp, and 2 bright solar systems outside our own, the very young HD100546 and the mature star HD69830. • We have learned that Hale-Bopp formed much earlier than Tempel 1, and that the families of comets and asteroids around other stars form and behave in much the same way as they did in our own solar system.

3. Protostar Relics of Planetary System Formation T < 104 yr Disk & Jet ~5 M¤ ~105 yr Comets, Proto-planets, Nebular Disks Planetary System + Small Relic Bodies (asteroids) ~107 yr T > 108 yr Orion Nebula HH30 HR4796

4. Where Comets Come From KBO’s, Pluto

5. Comet Structures (C/West 1975) Ion Tail Dust Tail 33,000,000 km (~0.2 AU) Coma Nucleus! (1-10 km) 80,000 km To Sun

6. Spitzer Observations of the Tempel 1 Ejecta Spitzer IRS I+45 Min 344 Spectral Points SNR 5 - 30 (2 error bars) 95% C.L. = 1.13 Simultaneous 5- 35 um > 16 Sharp Features Model : Sum of Mineral Emissions Carbonate (Chalk) (Pre-Post)/Pre = Ejecta/Pre-Impact Coma PAHs (Soot, Exhaust) Water Gas Amorph Carbno (Soot) Water Ice Phyllosilicates (Clay) Sulfidse (Fool’s Golds Pyroxene (Rocks) Olivines (Rocks) Lisse et al. 2006

7. Fire, Mud, & Ice : Tempel 1 Contains Xtal Silicates, Annealed at T > 1000K + Ices, Stable Only Below 200 K + Carbonates and Clays- Formed in Water Strong Radial PSN Mixing of material from inside the orbit of Mercury to outside the orbit of Neptune (turn-off when giant planet cores form) Crystal Silicates Carbonates Clays Comets Or Parent Body Aqueous Alterationover 4.5 Gyr (1) Impulsive Cratering (2) Long Term Water Vapor Processing

8. SST-IRS P/Tempel 1 Ejecta Spectrum Compared to Comets, Exo-Systems. - -Similar Spectra Due to Presence of Silicates, PAHs, Water, Sulfides. - Differences Due to Relative Compositions, T, Particle Size Disk Systems HD100546, HD69830, HD113766 Comets Hale-Bopp, SW3, SW1 10 Myr Be9V YSO w/ Disk Cavity ~15 Myr F3/F5 YSO 2-10 Gyr K0V w/ 3 Neptunes

9. Systems Studied Comet Hale-Bopp : A huge comet formed near the giant planets, early in the solar systems history. HD100546 (an infant giant star + forming solar system) HD69830 (a mature star slightly redder and about the same age as the Sun, with at least 3 planets).

10. 1.47 AU 1.5 AU JFC Tempel 1 Ejecta (SST; Lisse et al. 2006) JFC SW-3 B Fragment (SST; Sitko et al. 2007) Amorph Carbon PAHs Carbonates Sulfides Pyroxenes Olivines 2.8 AU 5.7 AU JFC/Centaur SW-1 Coma (SST; Stansberry et al. 2005) Oort Cloud Hale-Bopp Coma (ISO; Crovisier et al. 1997)) Carbonates Water Ice Smectite (clay) Pyroxenes Olivines Olivines Lisse et al. 2007 “Spectral Fingerprints” of Cometary IR Mineralogy T1 Spectral Model applied to other systems fits spectra well, extends results to Spitzer, ISO database. We can now dig down below the dominant silicate emissions to find other species. Hale-Bopp: No Fe-rich olivine. Much more water ice and amorphous carbon. Carbonates, clay. SW1, SW3 : Much amorphous silicates, Mg-rich olivine. Only water gas for SW3, ice for SW1.

11. K0V, 12 pc • K0V, T = 5400 K, 2 - 10 Gyr old, 12 pc distant • 3 Neptune Sized Planets @ 0.08, 0.16, 0.63 AU Lovis et al. 2006 “Mature” HD69830 B C D Asteroidal Dust Belt Lisse et al. 2007 T~ 400 K Super Comet or Asteroid? Carbonates PAHs absent Carbon attenuated Water Ice Sulfides absent Pyrox all crystalline Olivine Super-rich Lisse et al. 2007 Beichman et al. 2005 “Near-solar” star. Small, icy, ephemeral dust replenished by ongoing fragmentation. S.S. analogue : ~30 km radius P/D asteroid disrupted @ 1 AU. Karins/Veritas 5-8 Mya?

12. HD69830 (a mature star slightly redder and about the same age as the Sun, with at least 3 planets). B C Asteroidal Dust Belt Lisse et al. 2007 D - The dust around HD69830 is substantially different from that found for comet 9P/Tempel 1 or C/Hale-Bopp 1995 O1 and comet-dominated YSO HD100546. It lacks carbonaceous and ferrous materials but includes small icy grains.- The composition of the HD 69830 dust resembles that of a disrupted P or D-type asteroid. The amount of mass responsible for the observed emission is the equivalent of a 30 km radius asteroid.- The temperature of the dust implies that the bulk of the observed material is at ~1.0 AU from the central source, outside the outermost of 3 Neptune-sized planets detected by Lovis et al. (2006). - In our solar system, P and D-type asteroids are both large and numerous in the outer main belt and near Jupiter (e.g. the Hildas and Trojans).- Asteroids in our solar system have undergone similar major disruptive events to produce debris disk-like structures (e.g the Karin and Veritas families 5-8 Myrs ago).

13. Comparative IR Mineralogy of Young Stellar Objects HD100546 : Comet-like. Especially rich in Mg-rich olivine and amorphous pyroxene, water ice. We find the dust to be at ~13 AU, consistent with the inner disk cavity edge of Grady et al. 2005. HD113766: Mainly has Mg-rich olivine, Fe-rich sulfides, and xtal pyroxene. Little carbonates, clays, PAHs, or amorphous carbon present. Similar to S-type asteroid. NOT an older HD100546. Amorph Carbon HD100546 Disk Herbig Be9V >10 Myr X PAHs HD113766 Disk F3/F5 ~16 Myr Carbonates Water Ice Sulfides Clays Sulfides Pyroxenes Pyroxenes Olivines Olivines Lisse et al. 2007

14. Comet Hale-Bopp : A huge comet formed near the giant planets, early in the solar systems history. & HD100546 (an infant giant star + forming solar system) - We find similar emission signatures due to silicates, carbonates, phyllosilicates, water ice, amorphous carbon, and sulfides in the two ISO-observed systems, Hale-Bopp and HD100546, but there are significant differences as well. - T1, HB, and Hd100546 all show substantial emission due to silicates (rock forming materials), water, PAHs (soot, exhaust) and metal sulfides (fool’s gold).There are some differences : compared to Tempel 1, no Fe-rich olivines and few crystalline pyroxenes are found in Hale-Bopp. The silicate and PAH material in Hale-Bopp is clearly less processed than in Tempel 1, indicating an earlier age of formation for Hale-Bopp. - The observed material around HD 100546 is located ~13 AU from the central source, and demonstrates an unusual composition due to either a very different, non-solar starting mix of silicates or due to disk material processing during formation of the interior disk cavity and planet(s) in the system.

15. Summary • We have a new tool from the Deep Impact experiment, that allows us to understand the makeup of comets and asteroids, and to understand where and when comets and asteroids formed and evolved. • We have now successfully applied the tool to the ‘gold standard’ of comet studies, Comet Hale-Bopp, and 2 bright solar systems outside our own, the very young HD100546 and the mature star HD69830. • We have learned that Hale-Bopp formed much earlier than Tempel 1, and that the families of comets and asteroids around other stars form and behave in much the same way as they did in our own solar system.

17. By Measuring the Infrared Light from the Tempel 1 Ejecta, We Can Determine Dust • Composition • Temperature • Particle Size