Finding and characterizing extrasolar Earth analogs will rely on interpretation of the planetary system’s environmental context. The total budget and fractionation between C–H–O species sensitively affect the climatic and geodynamic state of terrestrial worlds, but their main delivery channels are poorly constrained. We connect numerical models of volatile chemistry and pebble coagulation in the circumstellar disk with the internal compositional evolution of planetesimals during the primary accretion phase. Our simulations demonstrate that disk chemistry and degassing from planetesimals operate on comparable timescales and can fractionate the relative abundances of major water and carbon carriers by orders of magnitude. As a result, individual planetary systems with significant planetesimal processing display increased correlation in the volatile budget of planetary building blocks relative to no internal heating. Planetesimal processing in a subset of systems increases the variance of volatile contents across planetary systems. Our simulations thus suggest that exoplanetary atmospheric compositions may provide constraints on when a specific planet formed.

寻找和表征太阳系外地球类似物将依赖于对行星系统环境背景的解释。C-H-O 物种之间的总收支和分馏敏感地影响陆地世界的气候和地球动力学状态，但它们的主要输送渠道受到的限制很差。我们将星周盘中挥发性化学和卵石凝结的数值模型与初级吸积阶段中星子的内部成分演化联系起来。我们的模拟表明，星子的圆盘化学和脱气在可比的时间尺度上运行，并且可以按数量级划分主要水和碳载体的相对丰度。因此，具有显着星子处理的单个行星系统显示，相对于没有内部加热，行星构建块的波动预算增加了相关性。系统子集中的微行星处理增加了行星系统中挥发性成分的差异。因此，我们的模拟表明，系外行星的大气成分可能会限制当一个特定的行星形成时。