Micrometeorids are microscopic objects moving in the interplanetary space of the Solar System. They are mostly produced by collisions among small solid bodies (i.g. asteroids) and by evaporation of icy bodies (i.g. comets) in the dust-production regions including the asteroid belt, the Kuiper belt and beyond. Micrometeorids comprise the near-Earth interplanetary dust clouds complex, known as the Zodiac cloud, which is visible in a clear moonless night sky as the Zodiacal light.

Micrometeorites represent an important sampling of the beginning of the Solar System and offer a unique opportunity to explore the geological processes that took place in the very first stages in the evolution of the protoplanetary disk. Some 40,000 tons of micrometeorids enter the Earth's atmosphere every year, largely dominating the annual mass flux of extra-terrestrial materials accreting on the Earth. The deposition  of micrometeorites is continuous everywhere on Earth. They represent the modern budget of micrometeorites although discrimination from terrestrial particles (natural or anthropogenic) are required and their survival relatively short due to their size and the active weathering processes taking place in most places on Earth. The majority of micrometeorites collected today are recovered from deep-sea sediments as well as in snow, ice and loose sediments in polar areas. They are fossilized micrometeorites that were deposited earlier in the Earth history.

Recently, naturally-formed quasicrystals together with several stable crystals have been discovered in fragments of the Khatyrka meteorite, i.e. a CV3 chondrite that comprises the primordial material of the Solar System. This states the quasicrystals as a new stable form of matter which can form in outer space and survive billions of years. Since other potential quasicrystal candidates have been reported including in the Suizhou L6 chondrite, in the carbonaceous diamond-bearing meteorite Hypatia, in cometary dust particles, as well as in a cosmic spherule recovered in the Nubian desert, Sudan. These newly observed types of minerals may only represent the tips of an iceberg of a myriad of novel crystals of incredible structural complexity that remains to be discovered in the Milky Way and perhaps elsewhere in the Universe. 

The micrometeorite project aims at:

  • Developing a new field sampling method for micrometeorites at the University of Uppsala  

  • Establishing a new collection of 'modern' and 'fossilized' micrometeorites for research purposes

  • Performing detailed petrophysical studies to access critical information about the parent bodies (e.g. asteroid formation and collisional histories)

  • Identifying potential key geological processes that occurred in the proto-solar disk.  

Earth and Space