Magnetic Remanence Recorded in the Bullet and Its Relation to Meteorite Entry.

Friday, 19 December 2014
Marian Takac1 and Gunther Kletetschka1,2, (1)Charles University in Prague, Faculty of Science, Prague, Czech Republic, (2)Academy of Sciences of the Czech Republic, Institute of Geology, Prague, Czech Republic
The direction in which the bullet was fired and by analogy a movement in which meteorite deccelerated during its atmosphere entry is often a mystery. We are solving this topic using guns and magnetic properties of projectiles. We use magnetic remanence as a tool to reconstruct at least part of the history of moving bodies. We are trying to characterize magnetic acquisition/loss of the bullets and than use acquired knowledge for bullet and meteorite tracing. The bullet is heated to high temperature by hot gases during firing. As it cools it gets its unique remanent magnetization signature. A unique signature is made out of multiple magnetic vectors, which are related to both direction of the geomagnetic field and direction of the trajectory of the projectile. The information provided by remanent magnetization can be used to retrieve at least some characteristics of the trajectory of the projectile. A similar process applies to meteorites, which are heated after entry into the atmosphere. Measurement results from bullets are being used for understanding the final history of meteorite descend. Our research is carried out experimentally. We made system for bullet magnetic modification that we use to track specific process of magnetic acquisition/loss. We have found significant potential in their magnetic remanence acquisition by choosing specific magnetic carriers and their grain size as part of the bullet composition.