A pristine cosmic laboratory
Ladakh's high-altitude, cold, and arid environment makes it a natural laboratory for collecting micrometeorites. Much like Antarctica, the region's glaciers and low level of terrestrial dust provide a clean environment to find and analyze extraterrestrial particles. These particles, typically ranging from 30 to 200 micrometers in size, are remnants of comets and asteroids that have traveled through our atmosphere. The total annual influx of this material to Earth is estimated to be around 5,200 tons, far exceeding the mass from larger meteorites.
The collection process in polar-like regions is methodical. Researchers melt large volumes of snow and ice, carefully filtering the water to separate the tiny cosmic spherules and unmelted particles. One series of expeditions in Antarctica identified over 1,280 unmelted micrometeorites and 808 cosmic spherules using this technique. Because glaciers form in layers over millennia, the trapped dust provides a vertical timeline. By sampling at different depths, scientists can study how the influx of cosmic material has changed over geological time, recording the history of our solar system.