Levison Harold F, Morbidelli Alessandro
Southwest Research Institute, Boulder, Colorado 80302, USA.
Nature. 2003 Nov 27;426(6965):419-21. doi: 10.1038/nature02120.
The 'dynamically cold Kuiper belt' consists of objects on low-inclination orbits between approximately 40 and approximately 50 au from the Sun. It currently contains material totalling less than a tenth the mass of the Earth, which is surprisingly low because, according to accretion models, the objects would not have grown to their present size unless the cold Kuiper belt originally contained tens of Earth masses of solids. Although several mechanisms have been proposed to produce the observed mass depletion, they all have significant limitations. Here we show that the objects currently observed in the dynamically cold Kuiper belt were most probably formed within approximately 35 au and were subsequently pushed outward by Neptune's 1:2 mean motion resonance during its final phase of migration. Combining our mechanism with previous work, we conclude that the entire Kuiper belt formed closer to the Sun and was transported outward during the final stages of planet formation.
“动态冷柯伊伯带”由距离太阳约40至约50天文单位的低倾角轨道上的天体组成。它目前所含物质的总质量不到地球质量的十分之一，这一数值低得出奇，因为根据吸积模型，除非冷柯伊伯带最初含有数十个地球质量的固体物质，否则这些天体不可能生长到目前的大小。尽管已经提出了几种机制来解释观测到的质量损耗，但它们都有很大的局限性。我们在此表明，目前在动态冷柯伊伯带中观测到的天体很可能是在约35天文单位范围内形成的，随后在海王星迁移的最后阶段因与海王星的2:1平均运动共振而被向外推。将我们的机制与之前的研究相结合，我们得出结论，整个柯伊伯带形成于离太阳更近的地方，并在行星形成的最后阶段向外迁移。
