We review recent progress in understanding how nebular dust and gas are converted into the planets of the present-day solar system, focusing particularly on the “Grand Tack” and pebble accretion scenarios. The Grand Tack can explain the observed division of the solar system into two different isotopic “flavours”, which are found in both differentiated and undifferentiated meteorites. The isotopic chronology inferred for the development of these two “flavours” is consistent with expectations of gas-giant growth and nebular gas loss timescales. The Grand Tack naturally makes a small Mars and a depleted, dynamically-excited and compositionally mixed asteroid belt (as observed); it builds both Mars and the Earth rapidly, which is consistent with the isotopically-inferred growth timescale of the former, but not the latter. Pebble accretion can explain the rapid required growth of Jupiter and Saturn, and the number of Kuiper Belt binaries, but requires specific assumptions to explain the relatively protracted growth timescale of Earth. Pure pebble accretion cannot explain the mixing observed in the asteroid belt, the fast proto-Earth spin rate, or the tilt of Uranus. No current observation requires pebble accretion to have operated in the inner solar system, but the thermal and compositional consequences of pebble accretion have yet to be explored in detail.

中文翻译：

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将尘埃转化为行星

我们回顾了了解星云尘埃和气体如何转化为当今太阳系行星的最新进展，特别关注“大头钉”和卵石吸积场景。Grand Tack 可以解释观察到的太阳系划分为两种不同的同位素“味道”，这两种同位素在已分化和未分化的陨石中都有发现。为这两种“味道”的发展推断的同位素年代学与对气体巨星增长和星云气体损失时间尺度的预期一致。Grand Tack 自然形成了一个小火星和一个耗尽的、动态激发的、成分混合的小行星带（如观察到的）；它快速建造火星和地球，这与前者的同位素推断生长时间尺度一致，但与后者不一致。卵石吸积可以解释木星和土星所需的快速增长以及柯伊伯带双星的数量，但需要特定的假设来解释地球相对较长的增长时间尺度。纯卵石吸积无法解释在小行星带中观察到的混合、快速的原地球自转速度或天王星的倾斜。目前的观测不需要卵石吸积在内部太阳系中运行，但卵石吸积的热和成分后果尚未得到详细探索。或天王星的倾斜。目前的观测不需要卵石吸积在太阳系内部运行，但卵石吸积的热和成分后果尚未得到详细探索。或天王星的倾斜。目前的观测不需要卵石吸积在内部太阳系中运行，但卵石吸积的热和成分后果尚未得到详细探索。