1. O. Absil & C. Eiroa with inputs from A. Roberge, D. Defrère, C. Beichman, W. Danchi, J.-C. Augereau, etc. O. Absil & C. Eiroa with inputs from A. Roberge, D. Defrère, C. Beichman, W. Danchi, J.-C. Augereau, etc.

2. We all live in a debris disk! Asteroid collisions Comet outgassing Dust is luminous (much more than the Earth) Dust is expected in any planetary system Kuiper belt: 40 K, 50 AUZodiacal disk: 300 K, 1 AU

3. ObservationsSimulations Earth at 1 AU Stark & Kuchner 2008

4. 10-100 zodi tolerable for closest targets Asymmetries need thorough investigation 2m 4m 6m 8m 12m

5. Shot noise: 100 zodi tolerable in average Preserves 75% of mission outcome Asymmetries: ~10 zodi tolerable

6. If Solar system is the rule, “Earth explorer” could just skip unsuitable systems Can afford to loose some time EZs interesting on their own What if EZ mode is around 10 zodi? 100 zodi? Is the distribution log-normal at all? Bimodal? 100 zodi? 10 zodi? < 1 zodi? Bad systems 100 10 1 1 0.1 0.01 1000

7. Detected since 1984 IRAS, ISO, Spitzer Sensitivity ~ 100 × solar Herschel Down to 1 × solar Actual distribution will soon be known for the cold parts What about warm parts? 100 × solar Bryden et al. 2006

8. Mid-infrared most suited Photometry Spitzer: IRS, MIPS Imaging 10-m telescopes, (JWST) Interferometry Keck Nuller, VLTI/MIDI Near-infrared can help Interferometry CHARA/FLUOR, VLTI/VINCI

9. IRS, MIPS 1000 zodi at 3-σ Large sample ~2% of systems Keck Interferometer Nuller 300 zodi at 3-σ Small sample (on-going) K-band interferometry 1000 zodi at 3-σ Small sample (on-going) ~20% of MS stars with large amount of hot dust?? EZs ≠ from solar zodi?? 100 10 1 1 0.1 0.01 KIN 300 zodi 1000

10. Solution #1 Use models to connect Kuiper belts with exozodis Problem: planetary system architecture matters! Solution #2 Survey exozodis to build histogram What should be the goal sensitivity? Probably around 30 zodi (3-σ) Solution #3 Characterise exozodis around all identified targets (need to wait for SIM or RV detections, and to reach 10 zodi)

11. LBTI Expect ~30 zodi at 3-σ Survey starting > 2012 60 targets: sufficient? Other possible nullers ALADDIN Balloon FKSI/Pegase Other instruments Small coronagraphs: need to be investigated

12. Invest in modelling Probability distribution (log-normal? bimodal? other?) How deep is enough? 30 zodi? Asymmetries: better predictions needed! Invest in LBTI Could greatly reduce the exozodi problem if it lives up to the expectations Support development of other exozodi finders ALADDIN, balloon, FKSI (share the same payload) Small coronagraphs?