Why lunar exploration?

• The gives witness of 4.5 billion years solar system history, particularly for the Earth-Moon system • Planetary processes can be studied in its simple state – Initial crust development – Differentiation – Impact and chronology – Volcanism und thermal evolution – Regolith processes and the early sun – Regolith processes and the current sun (evidence for global change) • Unique environment – Polar regions with ice? – Exosphere (space/surface interactions) – Stable platform Earth-Moon System

• Unique constellation – compelling essential? – random? •Origin – mega-impact? – other reasons?

• End-members of planetary evolution – dynamically changing young Earth – stable, cold, old Moon – fundamental for understanding planetary evolution • Stabilization of the system? – stability of the Earth’s climate? – implications for the evolution of life? Impact und impact chronology

• Lunar surface keeps a unique record of 4.5 billion years of small body flux in the inner solar system. – The accuracy of dating planetary surfaces and extrapolation of impact chronology to the outer solar system depends on the exact knowledge of the lunar chronology. – Datation of the origin and evolution of life on Earth (e.g. »sterilization events«).

– Implication of impact-induced »faunal break« on evolution – Knowledge about the hazard of earth crossing asteroids Geophysics: the “Core”

• The internal structure of the Moon is still unresolved – (Mega-)Regolith/Crust – Mantle – Core? – Density increases towards the center but much less than on Earth – Models are ambiguous due to the poor knowledge about density and thickness of the individual parts

Fe-Core with a radius of 220-450 km, about 5% of the lunar mass seems feasible (Earth’s core covers 33% of the total mass)

(Bild: C. Hamilton) Differentiation, Dichotomy, Mascons, Magnetic Field

• Global »magma ocean« – evidence? – planetary phenomena? – thickness? – mechanism? – differentiation? • Dichotomy of the lunar crust – Center of Mass ≠ center of figure: ~ 2 km • »Mascons« – only a few are correlated with maria

• Magnetic Field – Remnant magnetization in samples and on the surface (Lunar )

All this phenomena are poorly understood Lunar Volcanism

• Composition of magmas and global distribution of lava? • Start, duration and termination of volcanic activity?

High TiO2 Basalt Low TiO2 Basalt

Ages of basalt) Mineralogy und Geochemistry

Still uncertainties concerning the estimation of the content of major rock forming elements (Fe, Ti, Na, Mg, Ca, Al, Si) and minerals

Estimation of titanium based on and Lunar Prospector measurements, respectively

Mare basalt titanimu content

after Lucey et al., 2006 Lunar Regolith

camera/ MIMO: Spectrometers • Mapping the regolith’s 2m direct Radar – mineralogy SERTIS: – geochemistry 2m indirect – Particle size – polarization – maturity – porosity – solar wind implants – thermal inertia – stratigraphy of mega- impacts – vertical structure – transition to mega-regolith Morphology und Topography

• Essential for the understanding of geologic processes – Impact (exogene) – Volcanism (endogene) – Tektonism (endogene) Krater Keeler- Heavyside Graben

Lava sheets in Mare Imbrium

Images: Apollo

Ideal: Combination of high resolution stereo data with laser altimeter measurement (e.g.Mars: MOLA + HRSC) Mars: Combination Stereo/Laser

MGS-MOLA: 463 m/pixel MEX-HRSC: 50 m/pixel

2020 kmkm 2020 kmkm

Shaded Digital Elevation Models (DTM) – no images! HRSC: Hesperia Planum - »Butterfly Crater«

© ESA/DLR/FU Berlin (G. Neukum) Morphology und Topography

• Detailed mapping is essential for future exploration

– example: Crater • »Peak of Eternal Light« •Cold trap → ice? • accuracy of existing data ~4 km (x, y), ~500 m (z) – Global high resolution 3d image maps are missing

South polar region > 80° S (Clementine)

Left: Topography at Krater Shackleton/ Peak of Eternal Light (Clementine Stereo)

right: epithermal neutron flux at the south pole (Lunar Prospector) Shackleton Scientific Objectives of Lunar Exploration

• Provide the data base for the exploration and utilization of the Moon in the 21st century; geological, geochemical, geophysical

• Solve fundamental problems of planetology – The origin and evolution of the Moon as baseline for the understanding of the terrestrial planets. – Uniqueness of the Earth-Moon System. – Absolute calibration of the impact chronology for the datation of solar system processes. – Regolith as record for space environmental conditions.

• : composition and distribution of materials • Provide a high-resolution road map for further exploration What is needed

• Highest resolution in all wavelength ranges and global coverage: < 1m stereo < 10 m spectral (range 0.2 - 40 µm)

• Sub surface sounding, global coverage: regolith mapping - few meters deep with mm resolution - hundreds meter deep with m resolution

• Global gravity with 0.1 mGal resolution

• Magnetosphere globally with 0.25 nT resolution

This requirements are needed to improve existing data sets. LEO Payload configuration

Tochtersatelliten Flugrichtung Intersatellite Link Staubdetektor RadMo Kopf 1 Staubdetektor SPOSH X-Bd Antenne HRSC-L X-Bd Antenne SERTIS MIMO USMI VIS-NIR Langmuire SARS Nadir LCT Ka-/X-Bd Antenne Langmuire Deep Space RadMo Kopf 2 LEO Objectives

LEO is featuring a set of unique scientific capabilities w.r.t. other planned missions including: • (1) 100% global coverage of all remote sensing instruments with stereo resolutions of 1 m HRSC and ground resolution of the spectral bands of < 10 m. • (2) Besides the VIS-NIR spectral range so far uncovered, wavelengths in the ultraviolet (0.2 – 0.4 µm) and mid-infrared (7 - 14 µm) will be mapped globally. LEO Objectives

LEO is featuring a set of unique scientific capabilities w.r.t. other planned missions including: • (3) Subsurface detection of the regolith with a vertical resolutions of about 2 m down to a few hundred meters (radar) and on mm-scale within the first 2 meters (microwave-instrument) will investigate the regolith. LEO Objectives LEO is featuring a set of unique scientific capabilities w.r.t. other planned missions including: • (4) Detailed measurements of the gravity field and magnetic field from a low orbit (50 km) by two subsatellites and simultaneous Earth tracking, supported by a gravimeter and two independent magnetometers will provide high precision (0.1 mGal, 0.24 nT) and in addition will enable to geophysical investigate the far side.

Tochter 60 ± 30 km Tochter 2 1

Flight Direction

M M 2-2 50 ± 30 km 1-2 M2-1 M1-1

Moon LEO Objectives

LEO is featuring a set of unique scientific capabilities w.r.t. other planned missions including: • (5) The long mission duration of 4 year yields multiple high resolution stereo coverage and thus monitoring of new impacts; this is supported by a flash detection camera searching directly for impact events and dust detection in the exosphere. Payload Summary

Instruments range mass power daten rate HRSC-L 400 – 1000 nm 16 kg < 150 W 103 Mbit/s USMI 200 – 400 nm 2 kg 3 – 7 W 7 Mbit/s VIS-NIR 0.4 – 2.5 µm 2.7 kg 12 W 65 Mbit/s 7 – 14 µm (Spec) 5 Mbit/s (Spec) SERTIS 3,5 kg < 15 W 7 – 40 µm (µrad) 1,04 kbit/s (µrad) 1300 MHz / 1000 Mbit/s (SAR) SARSOUNDER 20 kg 60 W 23 cm (L-Band) 240 Mbit/s (Sound.) MIMO 0.5 – 150 mm 18 kg < 50 W 800 Mbit/Tag SPOSH 400 – 900 nm 2.5 kg 10 W ~ 23 Mbit/Tag MIGIM 0.01 – 1 Hz < 2 kg < 1 W < 1,27 kbit/s USO (Radio Science) 2,3 GHz (S-Band) 1.5 kg 5 W n.a. LunarMag < 1000 nT 1.5 kg 2 W 0,14 kbit/s RadMo 50 KeV – 300 MeV 6 kg 6 W 1 kbit/s Dust detector 10Mhz 2.5 kg 9.5 W 1 kbit/s total Instruments 73.2 kg 327.5 W Subsatellite 16.5 kg (21.7 W) Total payload 99,7 kg 348.3 W

total data volume (4 years): ~ 1280 Tbit data volume / day ~ 876 Gbit

LEO Objectives LEO is featuring a set of unique scientific capabilities w.r.t. other planned missions including: • (6) A low altitude orbit (50 km ± 25) Orbit inclination 85° conditions are stable but orbit parameters vary with time ∆V 1m per 99% coverage (conversion to 90° inclination required at the end of the mission to get 100% coverage) Lunar-Prospector Modell ΔV