The InSight mission to Mars landed within Homestead hollow on an Early Amazonian lava plain. The hollow is a 27‐m‐diameter, 0.3‐m‐deep quasi‐circular depression that shares morphologic and sedimentologic characteristics to degraded impact craters. Unlike the intercrater plains outside of the hollow, the interior lacks cobbles and is dominated by loose sand, granules, and pebbles. Fresher craters near the landing site exhibit meter‐scale bedforms in their ejecta and on their floors due to sediment trapping. The sedimentology of the interior fill of Homestead hollow suggests similar trapping. The hollow falls along a morphologic continuum that requires low rates of rim degradation and fill. Crater degradation rates (rim erosion plus filling) in the landing site decline nonlinearly through time from 10⁻² to 10⁻⁴ m/Myr as craters evolve to a hollow‐like form. Rim erosion rates are lower initially, at 10⁻³ m/Myr, but converge with degradation rates to 10⁻⁴ m/Myr. This implies that while filling plays an important role soon after crater formation, it is limited in later stages. Crater statistics indicate that the bulk of the fill occurred in the first ~50 Myr for Homestead hollow. The estimated maximum age of the hollow is ~400 to 700 Myr. This requires near‐zero fill aggradation and long‐term soil stability for the bulk of the crater's history. Fill stability manifests in Homestead hollow as a ~5‐ to 10‐cm‐thick duricrust, formed by exchanges of atmospheric water vapor with soil. The estimated degradation in the hollow requires ~2 to 3 m of sedimentary fill beneath the lander.

中文翻译：

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火星Homestead Hollow的InSight着陆点的撞击坑起源：对近地表地层，地表过程和侵蚀速率的影响

对火星的InSight任务降落在亚马逊河早期熔岩平原的霍姆斯特德空地中。凹陷是直径27毫米，深0.3微米的准圆形凹陷，其形态和沉积特征与退化的撞击坑相同。与凹陷外部的坑洼平原不同，内部没有卵石，主要是疏松的沙子，颗粒和卵石。由于沉积物被捕集，着陆点附近的较新的火山口在喷口和地面上都显示出米级的岩床。霍姆斯特德空洞内部填充物的沉积学。提示类似的陷阱。凹陷沿形态连续性下降，该形态连续性要求边缘降解和填充率低。 随着陨石坑演变成空心状，着陆点的陨石坑退化率（边缘侵蚀加填充）随时间从10 ^-2到10 ^-4 m / Myr呈非线性下降。轮辋侵蚀率最初较低，为10 ^-3  m / Myr，但随着退化率收敛到10 ^-4  m / Myr。这意味着，尽管在火山口形成后不久就起着重要的作用，但在以后的阶段它却受到限制。陨石坑的统计数据表明，填充物的大部分发生在Homestead空心的第一个〜50 Myr处。估计的最大空洞年龄为约400至700 Myr。在整个陨石坑的历史中，这需要接近零的填充物凝集和长期的土壤稳定性。填充稳定性在霍姆斯特德空洞中表现为约5至10厘米厚的榴du，由大气水蒸气与土壤的交换形成。估计空洞的退化需要着陆器下方约2至3 m的沉积物填充。