12-14 May, 2008SERENA, Santa Fe, NM 1 Mid-IR observations of
Mercurys Surface as related to MERTIS and PEL and BED (and SERENA,
of course) Slide 2 12-14 May, 2008SERENA, Santa Fe, NM 2 Ann L.
Sprague Lunar and Planetary Laboratory, Tucson, AZ, USA With many
collaborators over 2 decades: Surface studies:
GROUND-BASED--Kozlowski, Donaldson Hanna, Warell, Helbert,
Maturilli, Russel, Lynch, Witteborn, Lebofsky, Wooden, Hora, Kasis,
Cruikshank, Graps, Deutch MESSENGER--MASCS, GRNS, XRS: Domingue,
Vilas, McClintock, Izenberg, Holsclaw, Blewett, Head, Helbert,
McCoy, Murchie, Goldsten, Lawrence, Boynton, Feldman, Evans,
Nittler, Schlemm, Rhodes, Starr, Robinson, Solomon and the
MESSENGER TEAM Slide 3 12-14 May, 2008SERENA, Santa Fe, NM 3
Ground-based and MESSENGER VIS NIR spectroscopy demonstrated no or
very little FeO in Mercurys regolith Ground-based summary: Vilas et
al. (1994) A couple of detections of shallow Fe-bearing
clinopyroxene at both N and S at high latitudes, 170 to 230 E
Warell et al. (2006) MESSENGER MASCS McClintock et al. Submitted to
Science, 2008 Slide 4 12-14 May, 2008SERENA, Santa Fe, NM 4 What
might we see with the neutral and ionised particle analyser SERENA
(IFSI Italy) coming directly from Mercurys surface? Slide 5 12-14
May, 2008SERENA, Santa Fe, NM 5 a.55N, 27S; b.6E, 354W radar spots
B and A b. Same c. Same, also Kuiper-Murasaki craters d. Spots B
and A e. Same f. Same g. Caloris Basin h. 65N, 155W 0, 125W 9S,
105W i. 35S, 43-73W Sprague et al. 1998 Slide 6 12-14 May,
2008SERENA, Santa Fe, NM 6 atmospheric K emission surface
reflection in band continuum Adapted from Potter and Morgan PSS
(1997) Slide 7 12-14 May, 2008SERENA, Santa Fe, NM 7 The Mercury
Radiometer and Thermal Infrared Spectrometer (MERTIS) H. Hiesinger,
J. Helbert and the MERTIS Co-I Team Slide 8 12-14 May, 2008SERENA,
Santa Fe, NM 8 Plagioclase in some detail Data from PEL, Berlin
Emissivity Database, (Helbert et al. 2006) Slide 9 12-14 May,
2008SERENA, Santa Fe, NM 9 Credit: NASA/Johns Hopkins University
Applied Physics Laboratory /Carnegie Institution of Washington New:
There are composition differences between Caloris Basin, dark
plains material, and radar bright region C Slide 10 12-14 May,
2008SERENA, Santa Fe, NM 10 MDIS image of region measured in
mid-infrared spectral imaging discussed in this paper. This region,
also known as radar bright region "C" also has a prominent impact
crater centered at 114E, 11 N and its system of ejecta rays
appearing brighter against the darker heavily cratered surface
beneath. Slide 11 12-14 May, 2008SERENA, Santa Fe, NM 11 (left)
Goldstone-VLA X-band imaging showing radar-bright region "C" as the
dark irregular patch--adapted from Butler et al. (1993). (right)
Aricebo S-band dual polarization, delay-Doppler imaging showing
same region as heavily cratered. Only the regions north of the
"ambiguity line" approximately at the equator are relevant--
reproduced from Harmon et al. (2007). 210 to 270 W Longitude Slide
12 12-14 May, 2008SERENA, Santa Fe, NM 12 Key to Mineral types on
following slides Pyroxenes (e) enstatite: Mg-rich (h) hypersthene:
Mg,Fe (diop) diopside: Ca,Mg (hed) hedenbergite Fe,Ca Plagioclase
Na-rich ~90 down to 30 wgt% Na (and) andesine Na (olig) oligiclase
Na (lab) labradorite Na,Ca (byt) bytownite Ca,Na Olivine Mg-rich
variety ~70 to 97 wgt% >>>FO(70), FO(97) Garnet (p) pyrope
Mg - variety (g) grossular Ca-variety Slide 13 12-14 May,
2008SERENA, Santa Fe, NM 13 bright region "C" data-- black models
-- grey wide range of grain sizes 5 options for comparison 4
different opaque phases a) 90 spectral end members 180 spectral end
members b) rutile (TiO 2 ) permitted, rutile chosen c) ilmenite
permitted (FeTiO 3 ), but ilmenite not chosen d) perovskite (CaTiO
3 ) permitted, perovskite chosen e) troilite (FeS) permitted,
troilite chosen Slide 14 12-14 May, 2008SERENA, Santa Fe, NM 14
Enstatite.1 (Salisbury et al., 1988) SiO 2 56.70 TiO 2 0.01 Al 2 O
3 1.69 Fe 2 O 3 2.18 FeO4.79 MnO0.15 MgO35.25 CaO0.85 Na 2 O0.02
K2OK2O Total99.66 Hypersthene.1F (Salisbury et al., 1987) SiO 2
51.32 Al 2 O 3 4.89 FeO17.07 MgO26.09 CaO1.27 K2OK2O0.02 Na 2 O0.05
TiO 2 0.29 MnO0.35 Total101.33 orthopyroxene Slide 15 12-14 May,
2008SERENA, Santa Fe, NM 15 Labradorite.1F (Salisbury et al., 1987)
SiO 2 51.42 TiO 2 0.04 Al 2 O 3 30.76 Fe 2 O 3 0.24 FeO0.17 MnOnot
reported MgO0.05 CaO13.42 Na 2 O3.52 K2OK2O0.23 H2O0.04 Total99.89
Albite.1F (Salisbury et al., 1987) SiO 2 68.18 Al 2 O 3 20.07
FeO0.01 MgO0.02 CaO0.02 K2OK2O0.20 Na 2 O10.37 TiO 2 0.01 MnO0.01
Total99.88 plagioclase feldspar Slide 16 12-14 May, 2008SERENA,
Santa Fe, NM 16 Radar Bright C region results Mineral Type Limited#
end members Rutile TiO 2 Ilmenite FeTiO 3 Perovskite CaTiO 3
Troilite FeS Ortho- pyroxene 54 (e)33 (e) (h)17 (e)14 (e) (h)45 (e)
(h) Clino- pyroxene 0037 (hed)20 (d)0 olivine5 Fo(91)5 Fo(66)025 Fo
(88)6 Fo(79) plagioclase9 (lab)14 (lab) 00 orthoclase2435261821
garnet5 (p) 2 (g) 0.7 (p) 0.9 (g) 3 (p) 0 (g) 02 (p) 0 (g)
opaque0yes0 Slide 17 12-14 May, 2008SERENA, Santa Fe, NM 17 Color
and albedo controlled by maturity and composition Map units
statistically, next step is determine origin PC 2 interpreted to
represent compositional variation Caloris Basin smooth plains Low
albedo material Smooth plains Low albedo PC 2 MNF (minimum noise
fraction, similar to PC) 2-1-3 as R-G-B Low albedo material streak
From Robinson et al. LPSC 2008 Slide 18 12-14 May, 2008SERENA,
Santa Fe, NM 18 Next sequences from Donaldson Hanna et al 2008 EGU,
Vienna, Austria Slide 19 12-14 May, 2008SERENA, Santa Fe, NM 19
Caloris Basin Observations 8 April 2006 - 0080 9 April 2006 - 0070
Slide 20 12-14 May, 2008SERENA, Santa Fe, NM 20 Best Fit Models
Caloris Basin 9 April 2006 8 April 2006 EM TM Slide 21 12-14 May,
2008SERENA, Santa Fe, NM 21 Sanidine.3 (K,Na)Al 3 O 8 Salisbury et
al. (1991) SiO 2 67.43 Al 2 O 3 18.65 FeO0.59 MgO0.03 CaO0.02
K2OK2O7.38 Na 2 O5.38 TiO 2 0.03 MnO0.02 Total99.97 Orthoclase.3
KAlSi 3 O 8 Salisbury et al. (1991) SiO 2 64.81 TiO 2 0.02 Al 2 O 3
19.11 MnO0.03 K2OK2O13.51 Na 2 O1.69 FeO0.02 MgO0.04 CaO0.04
Total99.34 Potassium feldspars: K-spars Slide 22 12-14 May,
2008SERENA, Santa Fe, NM 22 Caloris Basin Results Merc0080Merc0070
Minerals2006-04-082006-04-09 K - Feldspar20% [sanidine]28%
[sanidine] Plagioclase15% [labradorite]12% [labradorite]
Orthopyroxene7% [enstatite] 5% [hypersthene] 10% [hypersthene]
Clinopyroxene19% [augite]27% [augite] Olivine
