近地小行星(162173) 1999 JU3的热惯量和表面特征研究  

Investigation of Thermal Inertia and Surface Properties for Near-earth Asteroid (162173) 1999 JU3

作　　者：余亮亮[1,2,3] 季江徽[1,2] 王素[1,2] 

机构地区：[1]中国科学院紫金山天文台,南京210008 [2]中国科学院行星科学重点实验室,南京210008 [3]中国科学院大学,北京100049

出　　处：《天文学报》2013年第6期537-549,共13页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(11273068;11203087;10973044;10933004);中国科学院新兴与交叉学科布局试点项目(KJZD-EW-Z001);中国科学院天文财务专项;江苏省自然科学基金项目(BK2009341);紫金山天文台小行星基金会资助

摘　　要：研究了隼鸟2号样品返回计划目标小行星(162173)1999JU3的表面物理与热性质.利用先进热物理模型(Advanced Thermal Physical Model,简称ATPM)研究了该小行星可能的表面热惯量分布,并进一步推测其表面物质特征.同时,估算了其有效直径和几何反照率,分别为D_(eff)=1.13±0.03 km,p_v=0.042±0.003,并得到其平均热惯量大约为(300±50)J·m^(-2)·s^(-0.5)·K^(-1).通过考虑1999 JU3可能的热惯量分布,推测其表面绝大部分区域可能由岩石碎末或细沙等松散物质覆盖,部分区域可能是粗沙和石头的混合物,极少的区域覆盖着大岩石.从这个意义上讲,隼鸟2号样品返回计划在工程上是可行的,其科学意义也是显而易见的.In order to obtain the substantial information about the physical and thermal properties of target asteroid （162173） 1999 JU3, which will be visited by Hayabusa 2 in a sample return mission, we estimate a possible thermal inertia distribution over its surface, and infer the major material component on it. In addition, the effective diameter and geo- metric albedo are derived, to be about Deer = 1.13-t-0.03 km, Pv = 0.0424-0.003, respectively. Moreover, the average thermal inertia is evaluated to be about （300 4-50） J. m-2. s-~＇5. K-1. As a result, a global thermal inertia distribution is assumed to describe the situation on the asteroid＇s surface. According to the outcomes derived with such a distribution, we infer that the major area over the surface of the proposed target may be covered by loose mate- rials, such as rocky debris, sand, and so on, but few bare rocks may exist in a very small region. In this sense, it is feasible for Hayabusa 2 to probe the proposed target, which will certainly bring back significant scientific outcomes after the successful sample return mission.

关 键 词：小行星 个别 1999 JU3 方法 数值 

分 类 号：P185[天文地球—天文学]