Interplanetary dust particles collected in the stratosphere: observations of atmospheric heating and constraints on their interrelationships and sources.
Interplanetary dust particles collected in the stratosphere: observations of atmospheric heating and constraints on their interrelationships and sources.
复制标题
在平流层收集的行星际尘埃粒子：大气加热的观测及其相互关系和来源的限制。
DOI：
10.1016/0019-1035(89)90028-6
复制
发表时间：
1989
期刊：
影响因子：
3.2
通讯作者：
John P. Bradley
中科院分区：
文献类型：
--
作者：
S. Sandford;John P. Bradley
大多数收集在平流层的行星际尘埃粒子（IDPs）属于三个主要类别之一，前两个主要由无水矿物橄榄石和辉石，第三个由含水层晶格硅酸盐。红外光谱和透射电子显微镜的研究表明，不同的IDP类别代表了不同类型的尘埃，这些尘埃在行星际空间中以单独的颗粒存在。收集到的层状晶格硅酸盐和辉石类中直径小于30微米的大部分IDP似乎在进入大气层期间没有被加热到600°C以上的温度。这些国内流离失所者在进入大气层期间经历的相对较低的最高温度意味着他们以低的地心相遇速度到达大气层顶部。这将这些粒子可能遭遇的轨道限制在相对圆形的椭圆轨道上。因此，这些境内流离失所者不太可能来自穿越地球的彗星或小行星。小行星和彗星具有低倾角和近日点以外的1.2 UA，似乎是最好的候选人的母体的辉石和层状晶格硅酸盐颗粒。化学和矿物学信息表明，辉石丰富的IDPs来自彗星和层状晶格硅酸盐丰富的IDPs来自小行星。收集到的以橄榄石为主的IDP似乎包括较大比例的加热超过600°C的粒子，这表明这些粒子是从更偏心的轨道捕获的。这一点，以及对几颗彗星中橄榄石的红外光谱特征的观察表明，这些粒子有彗星的起源。由于大部分收集的尘埃显然是从接近圆形的轨道上捕获的，而且目前在这样的轨道上没有合适的母体，这些结果提供了一个实验证实，坡印廷-罗伯逊效应作为一种非引力作用存在，在太阳系尘埃的轨道演化中很重要。
The majority of the interplanetary dust particles (IDPs) collected in the stratosphere belong to one of three major classes, the first two dominated by the anhydrous minerals olivine and pyroxene, and the third by hydrous layer-lattice silicates. Infrared spectroscopy and transmission electron microscopy studies show that the different IDP classes represent different types of dust that exist as individual particles in interplanetary space. The majority of the collected IDPs smaller than 30 μm in diameter in the layer-lattice silicate and pyroxene classes appear not to have been heated to temperatures above 600°C during atmospheric entry. The relatively low maximum temperatures experienced by these IDPs during atmospheric entry imply that they arrive at the top of the atmosphere with low geocentric encounter velocities. This limits the possible encounter trajectories for these particles to relatively circular, prograde orbits. As a result, it is unlikely that these IDPs are from Earth-crossing comets or asteroids. Asteroids, and comets having low inclinations and perihelia outside 1.2 UA, appear to be the best candidates for the parent bodies of the pyroxene and layer-lattice silicate particles. Chemical and mineralogical information suggests that the pyroxene-rich IDPs are from comets and layer-lattice silicate-rich IDPs are from asteroids. The collected IDPs dominated by olivine appear to include a larger fraction of particles heating above 600°C, suggesting that these particles were captured from more eccentric orbits. This, and the observation of the infrared spectral features of olivine in several comets suggest these particles have a cometary origin. Since much of the collected dust has apparently been captured from nearly circular, prograde orbits and since there are no appropriate parent bodies presently in such orbits, these results provide an experimental confirmation that the Poynting-Robertson effect exists as a nongravitational force important in the orbital evolution of dust in the Solar System.