The Europa Imaging System (EIS): High-resolution, 3-D insight into Europa's geology, ice shell, and potential for current activity Zibi Turtle, Alfred McEwen, Mike Bland, Geoff Collins, Ingrid Daubar, Carolyn Ernst, Leigh Fletcher, Candy Hansen, Ed Hawkins, Alex Hayes, Dave Humm, Terry Hurford, Randy Kirk, Nic Kutsop, Jenn McDermott, Amy Barr Mlinar, Francis Nimmo, Wes Patterson, Cynthia Phillips, Antoine Pommerol, Louise Prockter, Lynnae Quick, Ed Reynolds, Kim Slack, Jason Soderblom, Sarah Sutton, Nick Thomas, Helene Winters

1. EIS Overview Fig. 1: (Left) NAC mounted on 2-axis Designed for NASA's Europa Clipper Mission [1–3], DPUs in vault gimbal, (right) WAC, EIS combines narrow- and wide-angle cameras (Fig. and (middle) DPUs 1), each with framing and pushbroom imaging modes, in spacecraft vault. to explore Europa and address high-priority geology, EIS NAC EIS WAC composition, ice shell and ocean science objectives. Fig. 2: NAC and WAC Fig. 4: Galileo images of Europa at the scale of EIS global EIS data will be used to generate: cartographic and imaging covers >90% mapping: (left) Conamara Chaos at 54 m/pixel, image = 42 geologic maps; regional and high-resolution of Europa at ≤100-m km x 34 km; (right) Agenor Linea at 50 m/pixel with lower- topography; GIS, color, and photometric data products; pixel scale (17F12v2); resolution color and background, image = 135 km x 60 km. a database of plume-search observations; and a NAC imaging is NAC high-res stereo point ahead 30° point nadir point behind 30° geodetic control network tied to radar altimetry [4]. primarily framing; 5-km pushbroom 10-km pushbroom 5-km pushbroom WAC imaging is 5 km 10 km 5 km These datasets will allow us to: A B C primarily pushbroom. S/C motion constrain landform formation processes by

WAC & NAC filter layout (not to scale)

characterizing geologic structures, units, topography along pushbroom color surface - and global cross-cutting relationships [5] (Figs. 2–5) track WAC 3-line 10 km framing area stereo WAC 3-line identify relationships to subsurface structures and cross-track stereo potential near-surface water [e.g., 6] detected by ice- Fig. 5: (Top left & right) NAC penetrating radar [7] acquires high-resolution stereo using EIS the gimbal below 100-km altitude. investigate color variability (Fig. 3), correlate with filters: NUV BL GRN RED IR1 1µm U (Bottom right) WAC acquires 3-line compositions of individual features & regional units Galileo Violet Green Red 727 889 Infrared Filters: Continuum pushbroom stereo (see also Fig. 3). Wavelength search for evidence of recent or current activity, Fig. 3: Color pushbroom imaging using Filter Key Uses (nm) Surface mapping, stereo, including potential erupting plumes [e.g., 8–11] six, broad-band, stripe filters (top left, NAC:350–1050 Clear context imaging, best SNR for WAC: 370–1050 table) maps surface units to correlate faint targets, plume searches 3. Wide-Angle Camera (WAC) (Fig. 1) Surface color; plumes with NAC: 355–400 constrain variations in ice-shell thickness [12–13] NUV with geologic structures, topography, Rayleigh scattering WAC: 375–400 Surface color; Rayleigh 48° cross-track × 24° along-track FOV and 218- BLU 380–475 characterize surface clutter to aid interpretation of scattering with NUV compositional units [17] — MISE [18] Surface color; airglow (eclipse, GRN 520–590 µrad IFOV achieve 11-m pixel scale over a 44-km- nightside) deep and shallow radar sounding [7] spectral range 0.8–5.0 µm — as well RED Surface color 640–700 Surface color; continuum for wide swath from 50-km altitude IR1 780–920 as comparison to Voyager and Galileo H2O band characterize scientifically compelling landing sites Surface color; coarse-grained 1µm 950–1050 imaging (top right) to detect changes. ice H2O band Three-line pushbroom stereo (Fig. 5) along flyby and hazards by determining the nature of the surface ground-tracks generates DTMs with 32-m spatial at meter scales [14–16] (Figs. 5, 6) 2. Narrow-Angle Camera (NAC) (Fig. 1) scale and 4-m vertical precis. from 50-km alt. 2.3° cross-track × 1.2° along-track field of view (FOV) and 10-µrad instantaneous FOV (IFOV) 4. Detectors and Electronics achieve 0.5-m pixel scale over swaths 2-km wide and Identical radiation-hard 4k × 2k CMOS detectors typically 5- to 10-km long from 50-km altitude [20] with rapid readout for fast flybys and to 2-axis ±30° gimbal for independent targeting of: minimize radiation-induced noise near-global (>90%; Fig. 2) mapping at ≤100-m Framing and pushbroom imaging modes pixel scale; Galileo covered ~14% at ≤500 m/pixel Both cameras have color stripe filters (Fig. 3) regional stereo imaging (Fig. 2) mounted in front of detectors very high-res stereo imaging (Fig. 5) for digital APL radiation-hard data processing units (DPU) topographic models (DTMs) with 2-m spatial take advantage of the rapid, random-access readout scale, 0.25-m vertical precision from 50-km alt. of the CMOS arrays and use innovative real-time processing for pushbroom imaging [21], including: High-phase-angle observations to search for potential erupting plumes [8–11] WAC 3-line stereo (Fig. 5) 10-km pixel scale from 106 km allows EIS to take NAC and WAC 6-color pushbroom (Fig. 3) Fig. 6: Marguerite Bay, Antarctica at scales similar to EIS advantage of good illumination geometry for digital time delay integration (TDI) to enhance high-res imaging: GeoEye-1 image at 0.5 m/pixel forward scattering when distant from Europa signal-to-noise ratios (SNR) (http://www.satimagingcorp.com/gallery/geoeye-1/geoeye-1- antarctic-peninsula/) New Horizons LORRI heritage [19] data to measure & correct S/C jitter [22] References 8. 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