When I started to search for micrometeorites in 2009, one big question I confronted was what do they look like? Judging from the scientific publications at the time, illustrated with black and white scanning electron microscope (SEM) section images like the one below, they seemed to be subspherical. And the texts emphasized the presence of iron oxides magnetite and wüstite, so I imagined they were small metallic balls, which I searched for in the urban dust. Seven years later, when I finally broke the code and started to find real micrometeorites, I was surprised to learn that they were by no means metal spheres, but aerodynamic stones.
Since then, I have found more than four thousand micrometeorites, including under-documented varieties of extraterrestrial material. The best part? My work has inspired other collectors to take up the hunt. The variation seems endless, and nobody could have prepared me for the strange micrometeorites we find today.
One example that comes to mind is the recently found NMM 4002, a barred olivine (BO-type) micrometeorite measuring approximately 0.3 mm. To me, it looks like an inverted ice cream cone with two scoops. What happened here?
Perhaps we can find out, because as of yesterday we have got a new project started up with the brilliant astrophysicist Dr. Roar Skartlien from the Institute for Energy Technology (IFE). We are going to model the formation of micrometeorites varying entry speed, temperature, entry mass, entry angle, and so on.
We welcome Dr. Skartlien to our team and look forward to sharing the results with you here at Project Stardust. Make sure you connect with us on Facebook, Instagram, and Twitter to stay up to date with this exciting research! Enjoy!
2017 Research Paper Citation:
M.J. Genge, J. Larsen, M. Van Ginneken, M.D. Suttle; An urban collection of modern-day large micrometeorites: Evidence for variations in the extraterrestrial dust flux through the Quaternary. Geology 2017;; 45 (2): 119–122. doi: https://doi.org/10.1130/G38352.1