论文标题
在过去的十亿年中
Number of near-Earth objects and formation of lunar craters over the last billion years
论文作者
论文摘要
我们将大于15 km的月球陨石坑的数量与1.1 GA大于15 km的月数与如果在此期间接近地球对象及其轨道元素的数量接近相应的电流值，则可以以1.1 GA形成的陨石坑数量的估计值。对整个月球表面的陨石坑以及月球近侧的Oceanus procellarum和Maria区域进行了比较。在这些估计中，我们使用了与月球近地物体的碰撞概率的值以及火山口直径对撞击器大小的依赖性。根据不同作者的估计值，在母马区域，已知的哥白尼火山口的数量密度至少是其余月球表面的相应数字的两倍。我们的估计量与可能发生在最近300 Ma的大型主皮小行星可能发生的灾难性碎片后，这与近地物体的数量增长并不矛盾。但是，他们并不能证明这一增加。特别是，它们与Mazrouei等人的推论不冲突。 （2019年）290 MA以前，近地小行星与月球碰撞的频率增加了2.6倍。为了使地球对象（ECO）与地球发生碰撞一年等于10^-8的可能性，我们对陨石坑的数量的估计值与该模型一致，根据该模型，如果该模型的数量密度与Losia et al losia et al losia ket Al losia agation agation for Mare地区相同。 （2015年）对于D <30公里，与d> 30公里一样完整。由于ECOS与地球的这种碰撞概率以及该模型的碰撞概率，在最近的1.1 GA中，壁板速率可能是恒定的。
We compare the number of lunar craters larger than 15 km across and younger than 1.1 Ga to the estimates of the number of craters that could have been formed for 1.1 Ga if the number of near-Earth objects and their orbital elements during that time were close to the corresponding current values. The comparison was performed for craters over the entire lunar surface and in the region of the Oceanus Procellarum and maria on the near side of the Moon. In these estimates, we used the values of collision probabilities of near-Earth objects with the Moon and the dependences of the crater diameters on the impactor sizes. According to the estimates made by different authors, the number density of known Copernican craters with diameters D>15 km in mare regions is at least double the corresponding number for the remaining lunar surface. Our estimates do not contradict the growth in the number of near-Earth objects after probable catastrophic fragmentations of large main-belt asteroids, which may have occurred over the recent 300 Ma; however, they do not prove this increase. Particularly, they do not conflict with the inference made by Mazrouei et al. (2019) that 290 Ma ago the frequency of collisions of near-Earth asteroids with the Moon increased by 2.6 times. For a probability of a collision of an Earth-crossing object (ECO) with the Earth in a year equaled to 10^-8, our estimates of the number of craters agree with the model, according to which the number densities of the 15-km Copernican craters for the whole lunar surface would have been the same as that for mare regions if the data by Losiak et al. (2015) for D<30 km were as complete as those for D>30 km. With this collision probability of ECOs with the Earth and for this model, the cratering rate may have been constant over the recent 1.1 Ga.
