中文摘要：

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（AdvancedThermalPhysicalModel，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。ff=1．13±0．03km，pv=0．042士O．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1999JU3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．

英文摘要：

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.