标题： 冥王星哈乌梅亚上空间变化的陨石坑形态 显示英文标题

标题： Spatially variable crater morphology on the dwarf planet Haumea

摘要： 海尔梅亚，被认为是最外层柯伊伯带中第三大的天体，具有快速的3.92小时自转周期，导致其形状为三轴椭球体。在这里，我们首次详细预测了海尔梅亚的表面形态，特别是考虑了由于其独特形状带来的影响。鉴于观测结果表明海尔梅亚的表面主要由惰性水冰组成，我们预测了撞击坑特征，撞击坑很可能是在海尔梅亚上占主导地位的表面特征。在计算海尔梅亚的表面重力时，我们发现g值变化几乎达到两个数量级，从赤道主轴位置的最小值0.0126 m/s^2，到极点的1.076 m/s^2。我们还发现g值随着纬度呈现非单调减少。从最小表面重力位置的36.2公里到极点的6.1公里，简单到复杂撞击坑的过渡直径有所不同。赤道处的撞击坑预计体积更大，深度比高纬度地区的撞击坑大超过两倍，并且溅射物更厚。考虑到撞击溅射物逃逸的影响，我们计算得出海尔梅亚的逃逸速度从赤道到极点变化了62%。尽管极点的逃逸速度更高，但那里的撞击预计会有更高的溅射物逃逸质量分数。海尔梅亚可能在太阳系中是独一无二的，因为它表面的撞击坑形态存在显著变化，这些变化仅源于其表面重力大小的变化。 显示英文摘要

摘要： Haumea, thought to be the Kuiper Belt's 3rd most massive object, has a fast 3.92 hr rotational period, resulting in its shape as a triaxial ellipsoid. Here, we make the first detailed predictions of Haumea's surface morphology, considering in particular effects stemming from its unique shape. Given observations have indicated Haumea's surface to be predominantly inert water ice, we predict crater characteristics, with craters likely to be the predominant surface feature on Haumea. In calculating Haumea's surface gravity, we find that g varies by almost two orders of magnitude, from a minimum of 0.0126 m/s^2 at the location of the equatorial major axis, to 1.076 m/s^2 at the pole. We also find a non-monotonic decrease in g with latitude. The simple to complex crater transition diameter varies from 36.2 km at Haumea's location of minimum surface gravity to 6.1 km at the poles. Equatorial craters are expected to skew to larger volumes, have depths greater by a factor of > 2, and have thicker ejecta when compared with craters at high latitudes. Considering implications for escape of crater ejecta, we calculate that Haumea's escape velocity varies by 62% from equator to pole. Despite higher escape velocities at the poles, impacts there are expected to have a higher mass fraction of ejecta escape from Haumea's gravitational well. Haumea may be unique among planet-sized objects in the solar system in possessing dramatic variations in crater morphology across its surface, stemming solely from changes in the magnitude of its surface gravity.