Reevalution of Lunar Heat Flow Experiment: (Construction of a LUnar Thermal Model using Lunar Prospector Data)

月球热流实验的重新评估：（利用月球勘探者数据构建月球热模型）

基本信息

批准号：
12640413
负责人：
MIZUTANI Hitoshi
金额：
$ 2.43万
依托单位：
The Institute of Space and Astronautical Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640413/
关键词：
moon heat flow Prospector Clementine lunar crust gravity lunar toppography finite element method

项目摘要

Since lunar heat flow provides us with a unique means to estimate the bulk abundance of refractory elements in the moon, it is very important to re-assess the heat flow data obtained in the Apollo 15 and 17 missions, in terms of new global data obtained by recent lunar missions. In this paper, we analyze the Apollo heat flow data combining the topography, gravity field, and Thorium abundance data by Prospector mission and Clementine mission.First we investigated the effect of topography variation and mega-regolith thickness variation on the measured heat flow, using a finite element method. This effect is believed to be very significant on Apollo heat flow values, because the measurements at the both Apollo 15 and 17 sites are made near the boundary of lunar mare and highland where the topography and mega-regolith thickness changes drastically. The result of the numerical experiments show that the observed heat flow values at Apollo 15 and 17 sites are 10 to 20 % larger than the representative values of those sites.We construct two crustal-structure models by analyzing the topography and gravity field data one model (thick crust model) has a mean crustal thickness of 61 kin, and the other model (thin crust model) has a mean crustal thickness of 48 km. Combing these crustal models with Prospector's Thorium abundance map, we calculated the surface heat flow expected from the crustal models. Comparison of the theoretical heat flow values with the reevaluated Apollo heat flow values indicates that the bulk U abundance in the Moon is 20 to 30 ppb which is more or less similar to that of the upper mantle of the Earth. This suggests that refractory elements in the Moon are not so much enriched as those proposed by previous many workers on chemistry of returned lunar samples. The conclusion has significant influence of our view of the lunar origin.

由于月球热流为我们提供了一种独特的手段，可以估计月球中的难治元素的大量丰富性，因此根据最近的月球任务获得的新全局数据，重新评估Apollo 15和17任务中获得的热流数据非常重要。在本文中，我们分析了探矿者任务和克莱门汀任务的地形，重力场和thor的丰度数据的Apollo热流数据。首先，我们使用有限元方法研究了地形变化和巨型重石厚度变化对测量热流的影响。人们认为这种效果对阿波罗的热流动值非常重要，因为阿波罗15和17个地点的测量值都是在月球母马和高地边界附近进行的，在那里地形和大型制剂厚度急剧变化。数值实验的结果表明，在阿波罗15和17位点观察到的热流量比这些位点的代表值大10％至20％。我们通过分析两个地形结构模型来分析两种地形和重力野外数据一个模型（厚地壳模型）具有平均61个kin的外壳厚度，而collust模型的平均厚度为collust模型（collust colust thin）。将这些地壳模型与探矿者的thor丰度图梳理，我们计算了地壳模型预期的表面热流。比较理论热流量与重新评估的阿波罗热流动值表明，月球中的体积丰度为20至30 ppb，这与地球上地幔的大约相似。这表明月球中的耐火元素并不像以前的许多工人对返回的月球样品的化学作用所提出的那样丰富。结论对我们对月球起源的看法具有重大影响。

项目成果

期刊论文数量（25）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

吉田信介, 宮崎ゆか, 田中智, 宝来帰一, 水谷仁, 藤村彰夫, 平井研一: "LUNAR-Aペネトレータによる月熱流量計測 : 非定常解析による月熱流量の推定"2002年度合同学会予稿集. P036-P003 (2002)

Shinsuke Yoshida、Yuka Miyazaki、Satoshi Tanaka、Kiichi Horai、Hitoshi Mizutani、Akio Fujimura、Kenichi Hirai：“使用LUNAR-A穿透器测量月球热流：使用非定常分析估计月球热流”2002年联合学术会议论文集。 P036-P003 (2002)