A Wealth of Opportunities• The signature of water is pervasive in and around

the proposed ellipse, which resides ~600 km ENE of Opportunity

– Ellipse:• Over a dozen diverse layers rich in sulfates/hydrated minerals are

seen from orbit

• Many small craters have excavated underlying material in this flat, navigable site.

– Beyond the Ellipse:• Large water-related features

• MSL is well-equipped to assess this potential habitat for past life and it can answer many questions raised from the Opportunity Rover data.

• There was extensive fluvial erosion in this region of ancient Mars (maybe that’s why so many interesting things are exposed here?).

• Valley networks were forming before and after the Meridiani deposits.

• Bottom line: water was important here!

MOLA topography (pole-to-pole slope removed)

Hynek and Phillips, 2001

Hynek et al., 2002

Light toned, differentially eroded “etched” terrain was identified outcropping from under the hematite-bearing unit.

The unit was noted for the “many complex strata contained within”

> 500-m-thick unit is both high in albedo and thermal inertia.

Opportunity

More recent mapping shows the extent of etched terrain well beyond the hematite plain

= >3.3 × 105 km2

200 km0

THEMIS thermal inertiaHynek, 2004

proposedellipse

0 200 km

sulfate-richsulfate-rich sulfate-richsulfate-rich

ESA’s OMEGA instrument shows a strong sulfate/hydrated mineral signal from the etched unit (Gendrin et al., 2005; Arvidson et al., 2005)

200 km0

Zooming In

Ellipse is within a >200-km-long exposure of layered sulfate-rich bedrocks.

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atit

e-b

eari

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un

ith

emat

ite-

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g u

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THEMIS Day IR mosaic credit: ASU

etched unit

Many alternate Many alternate ellipses exist that ellipses exist that

are safe and are safe and scientifically scientifically interesting.interesting.

Ellipse Characteristics

Center: 0.0° N, 3.7°E

Elevation: -1.29 km (1σ = 64 m)

Max Slopes: 5 km=0.9°; 2 km=1.7°; MOLA shot-to-shot average of ~1°

IRTM Rock Abundance: ~7%

Thermal Inertia: 350-550 J m-2 K-1 s-1/2

Albedo: 0.19-0.21

Dust Index: Steve Ruff says it’s great.

Winds: Scot Rafkin says a-okay!

30 m contours

THEMIS VIS and MOC NA with MOLA colors

Ellipse Characteristics• Immediate science return.

– ANYWHERE you land will have interesting mineralogy and diverse stratigraphy.

• A number of small craters have excavated underlying material.

30 m contoursTHEMIS VIS and MOC NA with MOLA colors

Ellipse Characteristics• Many distinct, sulfate rich layers outcrop.

• A number of small craters have excavated underlying material.

Center: 0° N, 3.7°E

Elevation: -1.29 km (1σ = 64 m)

Max Slopes: 5 km=0.9°; 2 km=1.7°; MOLA shot-to-shot average of ~1°

IRTM Rock Abundance: ~7%

Thermal Inertia: 350-550 J m-2 K-1 s-1/2

Albedo: 0.19-0.21

30 m contoursTHEMIS VIS and MOC NA with MOLA colors

A

A’

A A’

The diverse layers suggest a changing depositional environment and/or varying

degrees of aqueous alteration.

V1

V2

MPFSp

Op

MSL

Mellon et al., 2000

An unexplored

region

Regional Water-Related Features

MOC NA E1600368

A diverse navigable surface

A number of craters to study

Lack of aeolian features

layer contacts in MO

C N

A

1 km

Eastern Meridiani Rationale• The Opportunity Rover has examined an upper section of

>500 m of ancient sulfate-rich layers.– While the mission changed our view of the planet, many questions

remain about the amount and role of water.

• Eastern Meridiani allows access to the heart of this section and MSL has the instruments to address the history of water.– Many immediately accessible, diverse layers are seen in and around

the safe and navigable ellipse.

– There’s the opportunity to link 2 landed data sets to the orbital context.

– Large-scale water-related features reside in and immediately beyond the ellipse.

1

• Landing MSL is this region would accomplish the overriding mission goal by assessing a habitable environment with a water-rich history.

Diverse, Ancient Sedimentary Outcrops and Water-Related Features Abound