Micrometeorites (MMs) are extraterrestrial dust particles, in the size range of tens of µm to mm, recovered from the Earth’s surface primarily from deep‐sea sediments, Antarctica, and also from space. The present collection of MMs (>50 µm) obtained by melting ~50 t of ice near the Maitri station, Antarctica, has allowed us to investigate the abundance and properties of the particles by an unbiased collection technique. The collection reveals a large quantity of extraterrestrial material in the ~80−140 µm size range. Previous collections have shown an abundance of particles at diameter ~200 µm, which is in contrast to our findings. This can either be explained by movement of material within the ice or a recent influx of smaller particles. The smaller particles (<80 µm) typically undergo atmospheric entry heating, contrary to earlier observations, which have suggested that they reach the Earth’s surface unmelted. Chondrules and refractory inclusions are rare in the collected MMs indicating that their contribution is only a small percentage. The Maitri station collection does not have a well‐constrained ice accumulation rate and terrestrial age. Nevertheless, based on matching the previous well‐documented flux calculation of Antarctica, we suggest a slow ice accumulation rate of <1.0 g cm⁻² yr⁻¹ near Maitri station.

中文翻译：

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探测从南极麦特里站收集的到达地球表面的外星尘埃的性质

微陨石是从地球表面主要从深海沉积物，南极洲以及太空中回收的地外尘埃颗粒，大小范围为几十微米至毫米。目前通过收集南极Maitri站附近的约50 t的冰融化而获得的MM（> 50 µm），使我们能够通过无偏收集技术研究颗粒的丰度和性质。该集合揭示了〜80-140 µm尺寸范围内的大量地球外物质。先前的收集显示直径约200 µm的大量颗粒，这与我们的发现相反。这可以用冰中物质的运动或最近涌入的较小颗粒来解释。较小的颗粒（<80 µm）通常会经历大气进入加热，与早期的观察相反，早期的观察表明它们未熔化就到达了地球表面。收集到的MM中很少有软骨和难熔夹杂物，表明它们的贡献仅占很小的百分比。Maitri站集合的冰积聚速率和陆地年龄没有严格限制。但是，根据与先前有据可查的南极通量计算结果相匹配的结果，我们建议缓慢的冰蓄积速率<1.0 g cm麦特里站附近的− ² 年− ¹年。