TY  - JOUR
A1  - Koch, Tamara
A1  - Spahr, Dominik
A1  - Tkalcec, Beverley J.
A1  - Lindner, Miles
A1  - Merges, David
A1  - Wilde, Fabian
A1  - Winkler, Björn
A1  - Brenker, Frank E.
T1  - Formation of chondrule analogs aboard the International Space Station
T2  - Meteoritics & planetary science
N2  - Chondrules are thought to play a crucial role in planet formation, but the mechanisms leading to their formation are still a matter of unresolved discussion. So far, experiments designed to understand chondrule formation conditions have been carried out only under the influence of terrestrial gravity. In order to introduce more realistic conditions, we developed a chondrule formation experiment, which was carried out at long-term microgravity aboard the International Space Station. In this experiment, freely levitating forsterite (Mg2SiO4) dust particles were exposed to electric arc discharges, thus simulating chondrule formation via nebular lightning. The arc discharges were able to melt single dust particles completely, which then crystallized with very high cooling rates of >105 K h−1. The crystals in the spherules show a crystallographic preferred orientation of the [010] axes perpendicular to the spherule surface, similar to the preferred orientation observed in some natural chondrules. This microstructure is probably the result of crystallization under microgravity conditions. Furthermore, the spherules interacted with the surrounding gas during crystallization. We show that this type of experiment is able to form spherules, which show some similarities with the morphology of chondrules despite very short heating pulses and high cooling rates.
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62670
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-626706
SN  - 1945-5100
N1  - We are grateful for financial support provided by the Dr. Rolf M. Schwiete Stiftung, the German Aerospace center DLR, NanoRacks LLC, DreamUp, Biovia, the BmWi (50JR1704) and DFG (BR2015/35-1; Wi1232/44-1), Nordlicht GmbH, and ZEISS.
N1  - Open Access funding enabled and organized by Projekt DEAL.
VL  - 56
IS  - 9
SP  - 1669
EP  - 1684
PB  - Wiley-Blackwell
CY  - Hoboken, NJ
ER  -