Margot J L, Brown M E
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
Science. 2003 Jun 20;300(5627):1939-42. doi: 10.1126/science.1085844.
The orbital parameters of a satellite revolving around 22 Kalliope indicate that the bulk density of this main-belt asteroid is 2.37 +/- 0.4 grams per cubic centimeter. M-type asteroids such as Kalliope are thought to be the disrupted metallic cores of differentiated bodies. The low-density indicates that Kalliope cannot be predominantly composed of metal and may be composed of chondritic material with approximately 30% porosity. The satellite orbit is circular, suggesting that Kalliope and its satellite have different internal structures and tidal dissipation rates. The satellite may be an aggregate of impact ejecta from an earlier collision with Kalliope.
一颗围绕22号司琴星运行的卫星的轨道参数表明，这颗主带小行星的整体密度为每立方厘米2.37±0.4克。像司琴星这样的M型小行星被认为是分异天体被破坏后的金属内核。低密度表明司琴星不可能主要由金属构成，可能由孔隙率约为30%的球粒状物质组成。卫星轨道是圆形的，这表明司琴星及其卫星具有不同的内部结构和潮汐耗散率。这颗卫星可能是早期与司琴星碰撞产生的撞击抛射物的聚集体。
