We propose to image Europa during its orbital eclipse by Jupiter. This will form the basis of an investigation into the nature of the tenuous atmosphere, electromagnetic environment and surface material of Europa. We will compare the FUV oxygen line at 1356A to the optical line at 6300A and seek optical auroral hydrogen emission in Halpha. With broad continuum filters, we will search for optical emissions from other atmospheric constituents and for fluorescence of the surface material, arising from the very high level of incident energetic particle radiation. The high spatial resolution of ACS will allow us to fully resolve scales of interest and allow us to distinguish easily the different terrains on Europa's surface. In particular we wish to compare luminesence in regions dominated by ice to those of potentially organic red material.

We will obtain a single ACS/SBC prism observation inside and outside eclipse. We will obtain one orbit that sweeps through all filters outside eclipse and the remaining four orbits will be inside eclipse. Three use broad filters and one uses the narrow band optical filters to seek auroral emission. 0 false 0.0 false false false false false false SUPPORTED SOLAR SYSTEM SATELLITE Jovian Moon STD=JUPITER STD=EUROPA NOT ECL U OF EUROPA BY JUPITER, OLG OF EUROPA BETWEEN 330.0 360.0 SOLAR SYSTEM SATELLITE Jovian Moon STD=JUPITER STD=EUROPA ECL U OF EUROPA-ECLIPSE BY JUPITER, SEP OF EUROPA JUPITER FROM EARTH GT 3.0" SOLAR SYSTEM SATELLITE Jovian Moon STD=JUPITER STD=EUROPA ECL U OF EUROPA-ECLIPSE BY JUPITER, SEP OF EUROPA JUPITER FROM EARTH GT 2.0" false -1 -1 (Tic-Visit :proposal-id 11085 :visit-id "02" :proposal-version -1 :trans-version "20070302" :date "27-Mar-2007 15:30:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11085 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11085 :visit-id "02" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2349 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11085 :visit-id "02" :orbit-number 2 :pcs-time 355 :si-vis-utilization 369 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 2 0 false -1 -1 (Tic-Visit :proposal-id 11085 :visit-id "04" :proposal-version -1 :trans-version "20070302" :date "27-Mar-2007 14:00:07.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 268896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11085 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11085 :visit-id "04" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2589 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0 false -1 -1 false -1 -1 (Tic-Visit :proposal-id 11085 :visit-id "07" :proposal-version -1 :trans-version "20070302" :date "27-Mar-2007 14:01:20.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "26" :si-bright-earth-limb-angle 20.0 :data-volume 224080 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11085 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11085 :visit-id "07" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2769 :al-overhead-at-end 120 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 1 0