马都拉洞穴陨石的轨迹、恢复和轨道历史
Trajectory, recovery, and orbital history of the Madura Cave meteorite
摘要：
2020年6月19日20：05：07 UTC，三个沙漠火球网络观测站在西澳大利亚上空观测到一个持续5.5秒的火球。流星体进入大气层的速度为$14.00 \pm 0.17$ km/s，沿$58^{\circ}$斜坡轨道从75公里高度下降到18.6公里。尽管观测站（29 $^{\circ}$）之间的三角形平面角度很差，而且距离观测站很远，但预测有一个受到良好约束的千级主质量落在西澳大利亚州马都拉以南。然而，由于轨迹的不确定性，预计搜索区域很大。幸运的是，在一次侦察旅行中，这块岩石很快就沿着通道被发现了。这颗重达1.072公斤的陨石名为马都拉洞穴，属于L5级普通球粒陨石。计算出的轨道属于Aten型（大部分包含在地球轨道内），这是继Bunburra Rockhole之后第二次在这样的轨道上观测到陨石。动力学模型显示，马都拉洞穴已经在近地空间存在了很长时间。据预测，前身流星体的近地天体动力学寿命为$\sim87$ Myr。这一奇特的轨道还表明，它是从主小行星带通过$\nu6$共振产生的，因此它的起源是在内带。这一结果有助于描绘出内带存在现今L型球粒陨石母体的图景。
英文摘要：
On the 19th June 2020 at 20:05:07 UTC, a fireball lasting 5.5 s was observed above Western Australia by three Desert Fireball Network observatories. The meteoroid entered the atmosphere with a speed of $14.00 \pm 0.17$ km s$^{-1}$ and followed a $58^{\circ}$ slope trajectory from a height of 75 km down to 18.6 km. Despite the poor angle of triangulated planes between observatories (29$^{\circ}$) and the large distance from the observatories, a well constrained kilo-size main mass was predicted to have fallen just South of Madura in Western Australia. However, the search area was predicted to be large due to the trajectory uncertainties. Fortunately, the rock was rapidly recovered along the access track during a reconnaissance trip. The 1.072 kg meteorite called Madura Cave was classified as an L5 ordinary chondrite. The calculated orbit is of Aten type (mostly contained within the Earth's orbit), the second time only a meteorite is observed on such an orbit after Bunburra Rockhole. Dynamical modelling shows that Madura Cave has been in near-Earth space for a very long time. The NEO dynamical lifetime for the progenitor meteoroid is predicted to be $\sim87$ Myr. This peculiar orbit also points to a delivery from the main asteroid belt via the $\nu6$ resonance, and therefore an origin in the inner belt. This result contributes to drawing a picture for the existence of a present-day L chondrite parent body in the inner belt.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
