Study of the Martian evolution based on high resolution mapping of the Martian magnetic anomaly

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05534
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Tsunakawa Hideo 東京工業大学, 理学院, 教授 (40163852)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 火星 / 磁気異常 / 地殻 / 進化 / 岩石型惑星 / 岩石磁気 / 月惑星探査

Outline of Final Research Achievements

We have analyzed Martian magnetic fields observed by Mars Global Surveyor (NASA). Applying the Surface Vector Mapping (SVM) method, we provided the magnetic anomaly maps on the Martian surface with high precision of spatial resolution. The results shows dominance of shorter wavelength components (about 5 degrees in latitude) than in previous studies. Strong magnetic anomalies are often seen at areas of high topography but not at low topography areas. This correlation suggests that main sources of the magnetic anomalies are contained in the Martian crust of <10 km depth. Such shallow magnetic carriers are not explained by the previous model. We also compared magnetic anomalies of Mars with those of Moon, Mercury and Earth on the basis of SVM maps. Similarities and differences of the crustal magnetic anomalies may reflect intrinsic and individual processes of the terrestrial planets and satellite.

Free Research Field

地球惑星電磁気学

Academic Significance and Societal Importance of the Research Achievements

本研究の主な学術的意義は２つある。一つ目は、火星の強い磁気異常を産み出す磁化ソースが、従来の研究とは逆に火星地殻浅部（深さ10㎞程度以下）と推定できることである。二つ目は、月観測で開発された磁気異常解析法を、火星だけでなく、水星・地球についても適用し、従来よりも高い空間分解能の磁気異常図を得て、地形・地質との比較を容易にしたことである。また、社会的意義とも考えられることとして、日本の火星探査将来計画（MMX）において、火星地殻形成・進化と火星衛星形成との科学ミッションを検討する上で、磁化物質という新たな観点を与えうる。