ARTEMIS and THEMIS Lunar Exploration: Probing Moon's Interactions with Sun

1. ARTEMIS Lunar Exploration THEMIS Extended Phase = THEMIS baseline + ARTEMIS

2. Overview • THEMIS prime (FY08, FY09) • Overview, orbits, examples of data and discoveries • THEMIS Extended Phase (FY10, FY11, FY12) • Extended THEMIS Baseline (3 probes) + ARTEMIS (2 probes) • Acceleration Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun • The magnetosphere • The solar wind • The lunar wake • ARTEMIS for Planetary • Exospheric Composition, Sputtering Rates • Crustal fields – wake deformation • Lunar interior sounding • Summary

3. TIME HISTORY OF EVENTS AND MACROSCALE INTERACTIONS DURING SUBSTORMS (THEMIS) • PRIME MISSION (FY08 - FY09) SCIENCE GOALS: • Primary: • “How do substorms operate?” • One of the oldest and most important questions in Geophysics • A turning point in our understanding of the dynamic magnetosphere • First bonus science: • “What accelerates storm-time ‘killer’ electrons?” • A significant contribution to space weather science • Second bonus science: • “What controls efficiency of solar wind – magnetosphere coupling?” • Provides global context of Solar Wind – Magnetosphere interaction RESOLVING THE PHYSICS OF ONSET AND EVOLUTION OF SUBSTORMS FIVE PROBES LINE UP TO TIME ONSET AND TRACK ENERGY FLOW IN THE TAIL

4. EFIs EFIa SCM ESA BGS SST Mission Ops UCB FGM Tspin=3s Ground Mission overview: Constellation in excellent health D2925-10 @ CCAS Release Probe instruments: ESA: ElectroStatic Analyzer(coIs: Carlson and McFadden)SST: Solid State Telescopes (coI: Larson)FGM: FluxGate Magnetometer(coIs: Glassmeier, Auster & Baumjohann)SCM: SearchCoil Magnetometer (coI: Roux) EFI: Electric Field Instrument (coI: Bonnell)

5. P1 P2 P3 P4 P5 TH-B TH-C TH-D TH-E TH-A Prime mission orbits (FY07-FY09) First 10 months(Feb 2007-Dec 2007) First year baseline orbit (FY08) 2007-03-23 Tail 12008-02-02 2007-06-03 YGSE Dayside 12008-08-08 Launch=2007-02-17 2007-07-15 XGSE Second year baseline orbit (FY09) 2007-08-30 2007-12-04 Tail 22009-02-18 Dayside 22009-09-16

6. First dissection of a detached FTE Sphere Dusk MP Sheath Discoveries Birth of storm-time ring current Sibeck et al.,GRL, in press Wang et al.,GRL, in press Liu et al.,GRL, in press First detection of remote signatures of FTE's: Dayside Traveling Compression Regions

7. Substorm trigger identified New results (1st tail season) Angelopoulos et al. submitted to: Science (embargo in effect)

8. THEMIS Extension (FY10,11,12)

9. ARTEMIS (P1,P2): FY10,11,12 FY10: Translunar injection FY11-12: 6mo Lissajous + 17 mo Lunar

10. ARTEMIS (P1,P2) • In the Magnetosphere, study: • Particle acceleration: X-line or O-line? • Reconnection: 3D character and global effects • Turbulence: Drivers and effects • Result: • Reveal 3D distant tail, dynamics • In conjunction with: • Solar wind monitors: • ACE, WIND, STEREO • Inner magnetosphere monitors: • Cluster, Geotail, FAST • Using the first: • Two point: dX, dY measurements • …at scales from ion gyroradius to several RE

11. ARTEMIS (P1,P2) • In the Solar Wind, study: • Particle acceleration at shocks • Nature and extent of elusive low-shear reconnection • Properties of inertial range of turbulence • Result: • Advance our understanding of particle acceleration and turbulence in Heliosphere • In conjunction with: • Other solar wind monitors: • ACE, WIND, STEREO • ARTEMIS is: • High-fidelity solar wind monitor • In beacon mode if requested • Using first of a kind: • …two point measurementsat scales 1-10 RE, ideal for study of particle evolution in shocks, at foreshock and inertial range of turbulence

12. ARTEMIS (P1,P2) • At the Moon/Wake: • Study 3D structure and evolution of wake • Result: • Advance our understanding of wakes at planetary moons, plasma void refilling around large objects (Shuttle, ISS, Hubble). • … to better separate lunar surface and interiorsignatures in the context of environmental influences • Using first of a kind: • …two point measurementsat scales 0.1-10 RE, ideal for two-point correlations within wake and between wake and solar wind

13. ARTEMIS and Lunar Exosphere ARTEMIS mass spectrometryof pickup ions plotted as “protons” • Lunar Exosphere: • Study composition, distribution of exospheric ions • Under a variety of solar wind conditions • Comprehensive instrumentation, ample statistics • Result: • Advance our understanding of lunarexosphere and its variability • Goes beyond WIND observations V,y H+ V,x He+ H2O+ S+ Solar Wind ARTEMIS-2 Exospheric Pickup Ion ARTEMIS-1 Hartle et al., 2005

14. ARTEMIS and Lunar Surface • Lunar Surface: • Study composition and distribution of sputtered ions • Understand crustal magnetic fields, surface charging • Remotely sense surface properties of lunar regolith • Result: • Advance our understanding of fundamental plasma interactions with planetary surfaces - with applications to Mercury, moons of Jupiter and Saturn, Pluto, KBOs, asteroids, etc. • Using first of kind: • …two point measurementsof ions and electrons near the Moon, with unprecedented energy coverage and resolution; beyond LP electron reflectometry capability Secondary electrons measured by Lunar Prospector [Halekas et al. 2008] Trace sputtered ions back to lunar surface ARTEMIS Secondary and photo-electrons accelerated from charged lunar surface reveal regolith surface properties

15. 1 Hood et al. 1999, GRL ARTEMIS and Lunar Interior • Unanswered questions about the lunar interior • Did the Moon form from a collision of Earth and a Mars size object? • How much of the moon formed from Earth and how from the impactor? • How deep was the lunar magma ocean? Does the Moon have a core? • Previous induction studies (Apollo, LP) support the lunar magma ocean hypothesis but are ambiguous due of low signal/noise ratio • ARTEMIS’s unique two point measurements allow us to separate external (inducing) and internal (induction response) fields at a wide range of frequencies, with much higher signal/noise ratio • Waves of T~0.1-1hr provide information on crust and upper mantle • Waves of T~1-5 hrs provide information on core (size, conductivity) • Study response to lobe perturbations: shocks and North-South crossings P1 P2 Core?

16. ARTEMIS and Planetary • In support of LRO: • ARTEMIS provide comprehensive monitoring of Lunar Space Environment • Complements LRO/CRATER measurements below 200keV • Supports LADEE and NAS’s Scientific Content of Exploration of the Moon to: • Understand the lunar atmosphere

17. Summary • THEMIS has delivered on its promises • Major discoveries from coast phase in GRL, JGR, SSR special issues • THEMIS+ARTEMIS: Continue to fully embrace community • All Data/Code Open; Help line: THEMIS_Software_Support; Mirror sites proliferating in US, Europe • ARTEMIS: Important for Heliophysics • ARTEMIS: a new mission with very high science value per dollar • In novel orbits, with comprehensive instrumentation • Has tremendous potential to conduct key Heliophysics science: from the moon • Addresses important Planetary questions: of the moon • Supports major Lunar program missions (LRO, LADEE)