JAXA’s Exploration of the Solar System Beyond the Moon and Mars

太陽系探査 — 宇宙からの全太陽系史 — 生命を育む環境の解明 地球の今を知る。 (a) 月が教える地球の進化 (b) 太陽が支配する地球環境 (c) 金星・水星・火星、姉妹惑星の素顔 (d) 近傍小惑星、地球の原材料を探す 生命惑星の存在理由を知る。 (a) 恒星太陽と地球、その未来 (b) 生命を育む「惑星系」の条件 (c) 更なる未踏域、太陽系全域への到達 (d) 宇宙における太陽系、その普遍性 太陽系の生い立ちを知る。 (a) 太陽と地球がたどる未来 (b) 火星、金星、地球になれなかった訳 (c) 木星、太陽系最大の惑星の素顔 (d) 原始小惑星・彗星、生命の原材料を PHASE 1 PHASE 2 PHASE 3

2025 年の宇宙観測・太陽系探査 宇宙の果ての観測 最初の銀河と最初のブラックホールの発見 第２の地球発見 重力波望遠鏡立ち上げ 太陽系全域への到達 彗星、メインベルト小惑星サンプルリターン 木星に到達、極周回、詳細探査 金星気球、火星飛行機実現、惑星気候の解明

Planet-C mission to Venus 2010 Launch- Arrival

Science themes of the Venus mission Atmospheric dynamics  Super-rotation  Meridional circulation  Meso-scale processes Lightning Cloud physics Detection of active volcanism

UV Near-Infrared Mid-Infrared Images from different altitude Lower stratosphere Upper troposphere Cloud Top

VEX(ESA) & Planet-C(JAXA) Optimization:Spectroscopy ⇔ Imaging Orbit:Polar ⇔ Equatorial Global images:High latitudes ⇔ Low latitudes

H. Yamakawa, H. Ogawa, H. Hayakawa, Y. Kasaba, T. Mukai and Mercury Exploration Working Group BepiColombo Mercury Magnetospheric Orbiter C. Noshi/RASC, Kyoto Univ. MMO Mercury Magnetospheric Orbiter MPO Mercury Planetary Orbiter Schedule 2012.mid Launch

MPO (Mercury Planetary Orbiter) ３ -axial Camera: Surface geology IR/UV/X/Gamma/neutron spectrometer: Compositon Magnetometer: Internal & Magnetospheric magnetic field Precise orbit determination: Gravitational field, Relativity etc. MMO (Mercury Magnetospheric Orbiter) Spin Magnetometer: Internal & Magnetospheric magnetic field Plasma particle, Electric field, Plasma waves: Magnetosphere - Structure, Dynamics, enegetic processes Energetic neutrals: Sputtered particles from Surface Na imager: Exosphere – Structure & Variation Dust: Interplanetary dust in the inner solar system ～ Low-altitude polar orbit: for Surface & Interior observations ～ Study of the planetary formation near the Sun ～ Elliptical polar orbit: for Magnetosphere & Exopsphere ～ First comparative study of the planetary magnetic field and Magnetosphere BepiColombo: Two Orbiters C. Noshi/RASC, Kyoto Univ. MMO Mercury Magnetospheric Orbiter MPO Mercury Planetary Orbiter

MMO (Mercury Magnetospheric Orbiter) Spin [Model Payload] Magnetometer: Internal & Magnetospheric magnetic field Plasma particle, Electric field, Plasma waves: Magnetosphere - Structure, Dynamics, energetic processes Energetic neutrals: Sputtered particles from Surface Na imager: Exosphere – Structure & Variation Dust: Interplanetary dust in the inner solar system MMO: Configuration & Target C. Noshi/RASC, Kyoto Univ. MMO Mercury Magnetospheric Orbiter Mercury will provide a unique chance of the Creation of comparative study of Magnetic Field & Magnetosphere of the terrestrial planets with internal B-field. Mercury will provide a unique chance of the Creation of comparative study of Magnetic Field & Magnetosphere of the terrestrial planets with internal B-field. ～ for Global coverage of Magnetosphere & Exosphere ～ Full-comparative study of the planetary magnetic field and magnetosphere

○ Magnetic field: Why does Mercury have? → Precise measurement of magnetic field structure enables the structure & origin of the internal fields. ○ Magnetosphere: No ionosphere & Different scales → Detailed structure/dynamics/energetic process show what is general / special in Magnetosphere physics. ○ Exosphere: Highly variability → Observations of structure & variations of Na Exosphere enable its generation/loss & origins. ○ Inter planetary space in the most inner solar system → Highest Mach number shocks (~40) which are only directly observed around the Mercury. Statistics & origins of Dusts in the inner solar system. Model of Magnetosphere / Exophere Magnetosphere different from the Earth pgenerates the comparative study of the planetary Magnetosphere. ? Discovery of magnetic field by Mariner10 Internal magnetic field describes the internal structure & its evolution Origin & Structure of Magnetic Field Why do planets have magnetic field? Mercury provides the first chance to compare the magnetic field with Earth. Magnetosphere: Similar or Different ? Mercury’s special Magnetosphere without Ionosphere will provide the another view of the planetary Magnetosphere. Science: Magnetic field & Magnetosphere [MMO]

○ Origin of peculier Composition → IR-Visible-UV spectroscopy 、 X/γ/neutron detection, and Neutrals/Plasmas from Surface provides keys for the origin of Mercury. ○ Origin of peculier Large core → Combination of Gravitational field & magnetic field mapping provides the detailed inner structure. ○ Detection of Polar Ice → γ/neutron observation will provide its proof. ○ Geology of old Surfaces → High-resolution imaging covering all area provides the history of the crust evolutions. Surface taken by Mariner10 Opposite side is unknown. History of Inner Solar System Magnetic field is connected to the peculier inner structure of Mercury, its large core. Mercury’s high density and composition tell us the initial stage of the planetary formation at the innermost region of Solar system. History of Inner Solar System Magnetic field is connected to the peculier inner structure of Mercury, its large core. Mercury’s high density and composition tell us the initial stage of the planetary formation at the innermost region of Solar system. Radius-Density relation Mercury is not on the trend. Science: Interior / Surface [MPO] Red: Commitment from Japanese scientists are planned.