文章来源:未知 文章作者:enread 发布时间:2014-08-25 07:27 字体: [ ]  进入论坛
The moon appears to be a tranquil1(安静的) place, but modeling done by University of New Hampshire and NASA scientists suggests that, over the eons, periodic storms of solar energetic particles may have significantly altered the properties of the soil in the moon's coldest craters2 through the process of sparking -- a finding that could change our understanding of the evolution of planetary surfaces in the solar system. The study, published recently in the Journal of Geophysical Research-Planets, proposes that high-energy particles from uncommon4, large solar storms penetrate5 the moon's frigid6, polar regions and electrically charge the soil. The charging may create sparking, or electrostatic breakdown7, and this "breakdown weathering" process has possibly changed the very nature of the moon's polar soil, suggesting that permanently8 shadowed regions, which hold clues to our solar system's past, may be more active than previously9 thought.
"Decoding10 the history recorded within these cold, dark craters requires understanding what processes affect their soil," says Andrew Jordan of the UNH Institute for the Study of Earth, Oceans, and Space, lead author of the paper. "To that end, we built a computer model to estimate how high-energy particles detected by the Cosmic Ray Telescope for the Effects of Radiation (CRaTER3) instrument on board NASA's Lunar Reconnaissance Orbiter (LRO) can create significant electric fields in the top layer of lunar soil."
The scientists also used data from the Electron, Proton, and Alpha Monitor (EPAM) on the Advanced Composition Explorer (ACE). CRaTER, which is led by scientists from UNH, and EPAM both detect high-energy particles, including solar energetic particles (SEPs). SEPs, after being created by solar storms, stream through space and bombard the moon. These particles can build up electric charges faster than the soil can dissipate(驱散) them and may cause sparking, particularly in the polar cold of permanently shadowed regions -- unique lunar sites as cold as minus 240 degrees Celsius11 and known to contain water ice.
Says Jordan, "Sparking is a process in which electrons, released from the soil grains by strong electric fields, race through the material so quickly that they vaporize little channels." Repeated sparking with each large solar storm could gradually grow these channels large enough to fragment the grains, disintegrating12 the soil into smaller particles of distinct minerals, Jordan and colleagues hypothesize.
The next phase of this research will involve investigating whether other instruments aboard LRO could detect evidence for sparking in lunar soil, as well as improving the model to better understand the process and its consequences.
"If breakdown weathering occurs on the moon, then it has important implications for our understanding of the evolution of planetary surfaces in the solar system, especially in extremely cold regions that are exposed to harsh radiation from space," says coauthor Timothy Stubbs of the NASA Goddard Space Flight Center.


1 tranquil UJGz0     
adj. 安静的, 宁静的, 稳定的, 不变的
  • The boy disturbed the tranquil surface of the pond with a stick. 那男孩用棍子打破了平静的池面。
  • The tranquil beauty of the village scenery is unique. 这乡村景色的宁静是绝无仅有的。
2 craters 1f8461e3895b38f51c992255a1c86823     
n.火山口( crater的名词复数 );弹坑等
  • Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
  • The battlefield was full of craters made by exploding shells. 战场上布满弹坑。 来自《现代英汉综合大词典》
3 crater WofzH     
  • With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。
  • They came to the lip of a dead crater.他们来到了一个死火山口。
4 uncommon AlPwO     
  • Such attitudes were not at all uncommon thirty years ago.这些看法在30年前很常见。
  • Phil has uncommon intelligence.菲尔智力超群。
5 penetrate juSyv     
  • Western ideas penetrate slowly through the East.西方观念逐渐传入东方。
  • The sunshine could not penetrate where the trees were thickest.阳光不能透入树木最浓密的地方。
6 frigid TfBzl     
  • The water was too frigid to allow him to remain submerged for long.水冰冷彻骨,他在下面呆不了太长时间。
  • She returned his smile with a frigid glance.对他的微笑她报以冷冷的一瞥。
7 breakdown cS0yx     
  • She suffered a nervous breakdown.她患神经衰弱。
  • The plane had a breakdown in the air,but it was fortunately removed by the ace pilot.飞机在空中发生了故障,但幸运的是被王牌驾驶员排除了。
8 permanently KluzuU     
  • The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
  • The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。
9 previously bkzzzC     
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
10 decoding b888b2fd35f4dd1fafb025cc18212418     
n.译码,解码v.译(码),解(码)( decode的现在分词 );分析及译解电子信号
  • We cannot add any other memory to this system without further decoding. 如果不增加译码,就不能使系统的存贮容量有任何扩展。 来自辞典例句
  • Examples using the 8250 will be presented in hardware section to clarify full-decoding schemes. 在硬件一节中有应用说明全译码方案8250的例子。 来自辞典例句
11 Celsius AXRzl     
  • The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
  • The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。
12 disintegrating 9d32d74678f9504e3a8713641951ccdf     
v.(使)破裂[分裂,粉碎],(使)崩溃( disintegrate的现在分词 )
  • As a poetic version of a disintegrating world, this one pleased him. 作为世界崩溃论在文学上的表现,他非常喜欢这个学说。 来自辞典例句
  • Soil animals increase the speed of litter breakdown by disintegrating tissue. 土壤动物通过分解组织,加速落叶层降解的速度。 来自辞典例句
TAG标签: moon solar soil