Abstract

This study is aimed at comprehensively analyzing and estimating the effects in gas dynamics, as well as mechanical and optical effects, from the Kyiv meteoroid that entered the terrestrial atmosphere and exploded over Bila Tserkva raion, Kyiv oblast (Ukraine). According to the International Meteor Organization (IMO), the apparent magnitude of the meteoroid was –18. According to our estimates, the luminous power was 215 GW with an effective duration of 2.4 ± 0.2 s, the total luminous energy was 25.2 ± 2.5 GJ, and the initial kinetic energy was 0.09 ± 0.01 kt of TNT or 375 ± 35 GJ. The initial mass of the cosmic body was estimated to be 0.89 ± 0.09 t, the volume was 0.250 ± 0.025 m³, and the size was 79 ± 3 cm. The initial velocity of the meteoroid reached 29 km/s. The inclination angle, i.e., the angle that the trajectory makes with the horizontal plane, was 32°. The explosion altitude equal to 38 km and the inclination angle equal to 32° give an estimate of 3.5 t/m³ for the material density, which is close to the rock density. The energy of the processes, the gas dynamics effects, and the mechanical and optical effects from the celestial body have been analyzed. The main release of energy associated with the deceleration of the fragments of the celestial body, which was defragmented under a dynamical pressure of approximately 2.5 MPa, took place in the region with a length of 2 km at an altitude of approximately 38 km. A quasi-continuous defragmentation is suggested to produce a mass distribution that follows a power law. The main parameters of the ballistic and explosive shock waves have been estimated. For the Mach number of 97, the radius of the ballistic shock wave is estimated to be approximately 77 m, and the fundamental period to be 0.7 s, which showed a dispersive increase from 3.7 to 11.5 s with the propagation path length increasing from 50 to 5000 km. The radii of cylindrical and spherical wavefront shock waves were approximately 0.28 and 0.34 km, and their fundamental periods were approximately 2.6 and 3.2 s, respectively. These periods increased from 9.5 to 30.0 s and from 11.1 to 35.1 s with an increase in the propagation path length from 50 to 5000 km. In the vicinity of the meteoroid’s explosion height, the relative excess pressure was a maximum. It decreased with a decrease in the altitude and increased with an increase in the altitude up to approximately 120–150 km, at which it attained values of approximately 6–7% and then further decreased down to a few percent. The absolute value of the excess pressure is estimated to be near the altitude of the explosion; subsequently it decreased with a decrease in the altitude down to 20–25 km and then increased further again. At the epicenter of the explosion, it is estimated to be approximately 94 Pa for the cylindrical wavefront and approximately 99 Pa for the spherical wavefront, which is not enough to damage objects on the ground. The excess pressure decreased with an increase in the altitude from 8–15 Pa to a few micropascals. Given an estimate of 2.4 s for the average duration of the effective light flash, the maximum power of the fireball is estimated to be 21 GW, and the power flux near the fireball (or more precisely, the cone 0.5 km in length and 2.4 m in diameter), is estimated to be 5.1 MW/m². At the same time, the temperature is estimated to be approximately 3100 K, and the Wien wavelength is estimated to be 9.4 × 10^–7 m.

中文翻译：

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基辅流星体的物理影响：第 1 部分

摘要

这项研究的目的是全面分析和估计进入地球大气层并在基辅州（乌克兰）白采尔科瓦地区爆炸的基辅流星体对气体动力学以及机械和光学效应的影响。根据国际流星组织 (IMO) 的数据，该流星体的视星等为 –18。根据我们的估算，发光功率为215吉瓦，有效持续时间为2.4±0.2秒，总发光能量为25.2±2.5GJ，初始动能为0.09±0.01kt TNT或375±35GJ。天体的初始质量估计为0.89±0.09t，体积为0.250±0.025m ³，尺寸为79±3cm。流星体的初速度达到了29公里/秒。倾角，即轨迹与水平面所成的角度，为32°。爆炸高度为 38 km，倾斜角为 32°，估计爆炸威力为 3.5 t/m ³为材料密度，接近岩石密度。分析了该过程的能量、气体动力学效应以及天体的机械和光学效应。与天体碎片减速相关的能量主要释放发生在长度为2公里、高度约为38公里的区域，天体碎片在约2.5兆帕的动压力下进行碎片整理。建议采用准连续碎片整理来产生遵循幂律的质量分布。弹道和爆炸冲击波的主要参数已经被估计。对于97马赫数，弹道冲击波的半径估计约为77 m，基本周期为0.7 s，显示出从3.7到11的色散增加。5秒，传播路径长度从50公里增加到5000公里。柱面和球面波前冲击波的半径分别约为0.28和0.34 km，基本周期分别约为2.6和3.2 s。随着传播路径长度从 50 公里增加到 5000 公里，这些周期从 9.5 秒增加到 30.0 秒，从 11.1 秒增加到 35.1 秒。在流星体爆炸高度附近，相对超压最大。它随着海拔的降低而降低，随着海拔的升高而增加，直到大约 120-150 公里，达到大约 6-7% 的值，然后进一步降低到几个百分点。超压绝对值估计接近爆炸高度；随后，随着海拔降低到 20-25 公里，它又下降，然后又进一步增加。在爆炸中心，圆柱形波前的压力估计约为 94 Pa，球形波前的压力约为 99 Pa，这不足以损坏地面上的物体。随着高度从 8-15 Pa 增加到几微帕，过剩压力降低。假设有效闪光的平均持续时间为 2.4 s，火球的最大功率估计为 21 GW，火球（或更准确地说，长 0.5 km、2.4 m 的锥体）附近的功率通量直径），估计为 5.1 MW/m 在爆炸中心，圆柱形波前的压力估计约为 94 Pa，球形波前的压力约为 99 Pa，这不足以损坏地面上的物体。随着高度从 8-15 Pa 增加到几微帕，过剩压力降低。假设有效闪光的平均持续时间为 2.4 s，火球的最大功率估计为 21 GW，火球（或更准确地说，长 0.5 km、2.4 m 的锥体）附近的功率通量直径），估计为 5.1 MW/m 在爆炸中心，圆柱形波前的压力估计约为 94 Pa，球形波前的压力约为 99 Pa，这不足以损坏地面上的物体。随着高度从 8-15 Pa 增加到几微帕，过剩压力降低。假设有效闪光的平均持续时间为 2.4 s，火球的最大功率估计为 21 GW，火球（或更准确地说，长 0.5 km、2.4 m 的锥体）附近的功率通量直径），估计为 5.1 MW/m 随着高度从 8-15 Pa 增加到几微帕，过剩压力降低。假设有效闪光的平均持续时间为 2.4 s，火球的最大功率估计为 21 GW，火球（或更准确地说，长 0.5 km、2.4 m 的锥体）附近的功率通量直径），估计为 5.1 MW/m 随着高度从 8-15 Pa 增加到几微帕，过剩压力降低。假设有效闪光的平均持续时间为 2.4 s，火球的最大功率估计为 21 GW，火球（或更准确地说，长 0.5 km、2.4 m 的锥体）附近的功率通量直径），估计为 5.1 MW/m² . 同时，温度估计约为 3100 K，维恩波长估计为 9.4 × 10 ^–7 m。