0 Assigned ID: 7229 ----- Attempting Submission 1 (Wed Apr 15 22:24:40 GMT 2026) ----- HST Phase I Proposal 7229 successfully submitted. Receipt: # 7229-1 ----- Attempting Submission 2 (Wed Apr 15 22:36:31 GMT 2026) ----- HST Phase I Proposal 7229 successfully submitted. Receipt: # 7229-2 ----- Attempting Submission 3 (Thu Apr 16 23:54:05 GMT 2026) ----- HST Phase I Proposal 7229 successfully submitted. Receipt: # 7229-3 ----- Attempting Submission 4 (Fri Apr 17 00:00:21 GMT 2026) ----- 0 We propose to use the ACS/WFC polarimetric mode on HST to obtain the first high-SNR, multi-wavelength polarization maps of Jupiter's entire disk in four SDSS filters (g, r, i, z) at a resolution more than five times higher than any prior measurements. These observations will enable us to: (1) retrieve aerosol phase functions and vertical layering across belts, zones, and the Great Red Spot; (2) detect the predicted transition from positive to negative polarization at intermediate latitudes; (3) quantify the spatial variability of the polar stratospheric haze, which is linked to auroral chemistry and magnetospheric activity; and (4) separate stratospheric and tropospheric aerosol contributions. The polar regions exhibit strong radial polarization (up to 11.5%) due to unique aggregate particles; our maps will resolve polar haze structure at ~1400 km scales and track temporal variability. The data will be directly coordinated with Juno's perijove passes in February 2027, linking in situ plasma and auroral measurements to haze distribution. Furthermore, Jupiter serves as the nearest giant-planet analog for exoplanets; our polarization maps provide a critical empirical benchmark for interpreting unresolved exoplanet polarimetry. Deliverables include fully calibrated cylindrical maps of Stokes I, Q, U, polarization degree and angle, a catalog of feature properties, and open-source radiative transfer models. This program maximizes HST's unique polarimetric capability and leaves a lasting legacy for planetary and exoplanet science. Dr. Lifan Wang is an expert on astronomical polarimetry. Dr. Alex Filippenko is an expert on tobservational astronomy including polarimetry. Dr. Ping Yang is an expert on atmospheric science and radiative transfer. Solar System Astronomy Exoplanets and Exoplanet Formation 0 false false false false false false true SUPPORTED SOLAR SYSTEM 5.6 - 5.8 mag per square arcsecond EARTH ACS/WFC Imaging No Yes F435W ACS/WFC Imaging No Yes F625W ACS/WFC Imaging No Yes F775W ACS/WFC Imaging No Yes F814W