Charon: Geologic Map of New Horizons’ Encounter Hemisphere, IIIS.J. Robbins0,1, J.R. Spencer1, R.A. Beyer2,3, P. Schenk4, J.M. Moore3, W.B. McKinnon5, R.P. Binzel6, M.W. Buie1, B.J. Buratti7, A.F. Cheng8, W.M. Grundy9,

I.R. Linscott10, H.J. Reitsema11, D.C. Reuter12, M.R. Showalter2, G.L. Tyler1, L.A. Young1, C.B. Olkin1, K. Ennico3, H.A. Weaver8, S.A. Stern1,the New Horizons Geology & Geophysics Investigation Team, LORRI Instrument Team, MVIC Instrument Team, and the New Horizons Encounter Team

0stuart@boulder.swri.edu, Southwest Research Institute, @DrAstroStu, 1Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302. 2Sagan Center at the SETI Institute. 3NASA Ames Research Center, Moffett Field, CA 84043. 4Lunar and Planetary Institute, Houston, TX. 5Washington University in St. Louis, St. Louis, MO.6Massachussetts Institute of Technology, Cambridge, MA. 7NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA. 8The Johns Hopkins University, Baltimore, MD. 9Lowell Observatory, Flagstaff, AZ. 10Stanford University, Stanford, CA. 11Ball Aerospace (retired), Boulder, CO. 12NASA Goddard Space Flight Center, Greenbelt, MD.

• Basemap control as of March 2017, and Map reflects Jan-uary 2016 SPICE solutions.

• Basemap is LORRI mosaic with merged MVIC scan.

• Line art is being redrafted with March 2017 SPICE solu-tions, and being expanded northward.

Tectonics Map

“Vulcan Planum” Map

Units

Crb

Ej1

Ej2

Ls

Dm

Mo1

Mo2

Pg1

Pg2

Rt

Sm

Sme

Cr

Linear Featurescrest of buried cratercrest of crater rimdepression margingraben tracegrooveridge crestcatena

broad warp

scarp basescarp crest

Geologic Contactsmap boundaryboundary, certainboundary, approximate

Surface Featuresdark-colored ejecta

light-colored ejecta

colors used only in tectonics map

Buried Crater

Ejecta Type 1

Ejecta Type 2

Landslide

Depressed Material

Mons Type 1

Mons Type 2

Patterned Ground Type 1

Patterned Ground Type 2

Rough Terrain

Smooth Terrain

Smooth Terrain, Elevated

Crater

References &Acknowledgments[1] Cheng, A.F. et al. (2008) Long-Range Re-

connaissance Imager on New Horizons. Space Sci. Rev. 140, 187-215. doi: 10.1007/s11214-007-9271-6.

[2] Reuter, D.C. et al. (2008) Ralph: A Visible/In-frared Imager for the New Horizons Plu-to/Kuiper Belt Mission. Space Sci. Rev. 140, 129-154. doi: 10.1007/s11214-008-9375-7.

[3] Schenk, P. et al. (2016) Topography of Pluto and Charon: Impact Cratering. Lunar & Planet. Sci. Conf. 47, Abstract #2795.

[4] Robbins, S.J. et al. (2017) Craters of the Pluto-Charon System. Icarus 287, 187-206. doi: 10.1016/j.icarus.2016.09.027.

[5] Beyer, R.A. et al. (2017) Charon Tectonics. Icarus 287, 161-174. doi: 10.1016/j.icarus.2016.12.018.

[6] Beyer, R.A. et al. (in prep.) Geology of Char-on’s Smooth Southern Plains. in prep. for Icarus.

This work was funded by NASA’s New Horizons mission.

Data SourcesBasemap: Panchromatic LORRI [1] and MVIC [2] images at up to 160 m/px. Mapping area pixel scale at least 850 m/px. Solar in-cidence and emission angles are non-uniform and this, with non-uniform pixel scale across datasets, complicates mapping.

Topography: Solutions over most of the encounter hemisphere at up to 100 m accuracy, down to 850 m accuracy [3].

Composition: 4-color mosaics from MVIC at 650 and 1500 m/px. Hyperspectral imaging at 5,000 m/px of most of encounter hemisphere, composition maps are in progress to new basemap.

Crater Maps: Craters from [4] and D ≥ 15 km used in this map.

Incidence & Emission Angles

-90

-60

-30

0

30

60

90

Latit

ude

360270180900

Longitude

90

80

70

60

50

40

30

20

10

0

Incidence Angle (0°=noon, 90°=terminator)

-90

-60

-30

0

30

60

90

Latit

ude

360270180900

Longitude

90

80

70

60

50

40

30

20

10

0

Emission Angle (0°=directly below

spacecraft)

area in permanent winter for next several decades

area in permanent winter for next several decades

Pixel Scale

-90

-60

-30

0

30

60

90

Latit

ude

360270180900

Longitude

0.1

2

3456

1

2

3

456

10

2

34

Pixel Scale (km/px)

16

14

12

10

8

6

4

2

0

Perc

ent

of S

urfa

ce p

er P

ixel

Sca

le

6 80.1

2 4 6 81

2 4 6 810

2 4

Pixel Scale (km/px)

100

80

60

40

20

0

Cumulative Percent of Surface per Pixel Scale

Histogram Cumulative

19.6% of surface not observedmapping area

area in permanent winter for next several decades

Mapping ProgressDone: Mapped global tectonics [5] and Vulcan Planum area [6] using SPICE from Sept. 2016.

In Progress: Redrafting to March 2017 SPICE; extending map northwards based on albedo rather than topography.

To Do:• Merge shadow/topography-based

map (south) with albedo (north) map units if possible

• Incorporate topography and min-eralogy

• Develop chronostratigraphy.

Mapping DetailsGlobal

Approximate Map Area: 60% of disk*

Full Map Scale: 1:3Mprinted map 50”

Mapping Scale (6×): 1:500,000

Vertex Spacing: 2.5 km (⅘ mm)

Min. Crater: 30 km (1 cm)

Min. Feature Length: 15 km (½ cm)

Min. Unit: 250 km2

*Map area covers images taken within a few hours of closest approach and closely corre-sponds with the areas imaged at ≲1 km/px. Southern margin of “map boundary” corre-sponds to terminator topography and is not fully reflected in incidence / emission angle and pixel scale maps. Area is ≈2,800,000 km2.

Vulcan Planum (informal name)

Approximate Map Area: 485,000 km2

Scale: 1:500,000

Mapping Scale: 1:100,000

Vertex Spacing: 2.5 km

Min. Crater: 15 km (3 cm)

Min. Feature Length: 5 km (1 cm)

Min. Unit: 50 km2

example of offset due to different versionsof the basemap being used; all lines mustbe redrafted to the same, most recent solution