THE MICROMETEORITES PROJECT
Micrometeorites, being microscopic objects traversing the interplanetary space within the Solar System, are primarily generated through collisions among small solid bodies, such as asteroids, and through the evaporation of icy bodies, such as comets, in the dust-production regions, which include the Kuiper belt, the asteroid belt, and beyond. These extraordinary particles comprise the Zodiac cloud, which is visible in clear moonless nights as the Zodiacal light.
In terms of scientific significance, micrometeorites are crucial in understanding the beginning of the Solar System and the geological processes that occurred in its early stages, providing unique opportunities for investigation into the evolution of the protoplanetary disk. Notably, approximately 40,000 tons of micrometeorites enter the Earth's atmosphere every year, dominating the mass flux of extra-terrestrial materials accreting on the planet. Although the deposition of micrometeorites is ubiquitous and continuous across the Earth, discrimination from terrestrial particles, whether natural or anthropogenic, is a requisite consideration. The majority of micrometeorites recovered today are typically obtained from deep-sea sediments, apart from samples in snow, ice, and loose sediments found in polar regions, constituting fossilized micrometeorites that were deposited earlier in Earth's history.
Recently, naturally-formed quasicrystals were discovered in fragments of the Khatyrka meteorite, denoting them as a new stable form of matter that could form and survive in outer space for billions of years. Other previously discovered quasicrystal candidates are from a wide range of sources, including the Suizhou L6 chondrite, the carbonaceous diamond-bearing meteorite Hypatia, cometary dust particles, and a cosmic spherule found in the Nubian desert. These rare minerals signify only a fraction of the potentially infinite numbers of novel crystals of exceptional structural complexity yet to be discovered in the Milky Way and other corners of the Universe.
The micrometeorite research project at the University of Uppsala aims to develop a novel field sampling method for micrometeorites, create a new collection of 'modern' and 'fossilized' micrometeorites for research purposes, perform detailed petrophysical studies, and gain important insights into the parent bodies' asteroid formation and collisional histories as well as identify key geological processes that occurred in the proto-solar disk.
