利略磁力计测量:在欧罗巴的地表下有一个海洋的更强的案例
M G Kivelson1, K K Khurana, C T Russell
1Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, USA. mkivelson@igpp.ucla.edu
概括
利略 利略 利略 利略
科学领域:
- 行星科学 行星科学
- 磁动力学 磁动力学
- 天体生物学 天体生物学
背景情况:
- 木星的卫星欧洲是寻找外星生命的首要目标.
- 之前的任务表明存在地下海洋,但直接证据仍然难以捉摸.
研究的目的:
- 为了研究欧罗巴的内部磁场.
- 要确定欧罗巴是否具有永久磁二极极矩或诱导的磁二极极矩,表明导电层.
主要方法:
- 2000年1月3日,利略航天器在欧洲的近距离飞行中分析了磁场数据.
- 模拟欧洲磁场对木星磁层的反应.
主要成果:
- 利略的磁力计检测到磁场变化与诱导场一致.
- 这些变化与预测流载层的模型一致,可能是全球盐水海洋,位于欧罗巴冰的地下.
结论:
- 欧罗巴磁场所观察到的时间变化强烈支持地下液态海洋的存在.
- 这一发现增强了欧罗巴的潜在可居住性,需要进一步研究.
相关概念视频
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A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
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The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
Magnetic field lines follow several hard-and-fast rules:
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The magnetic flux measures the number of magnetic field lines passing through a given surface area. The SI unit for magnetic flux is the weber (Wb). Magnetic flux is a scalar quantity. It depends on three factors: the strength of the magnetic field B, the area through which the field lines pass, and the relative orientation of the field with the surface area.
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