The intense energy of an asteroid impact causes melting and vaporization of upper layers of Earth’s crust. Some of this material is ejected away from the site of impact in a hot plume of expanding rock vapor and melt. 

Artist’s rendition of an asteroid impact on Earth. The impact melts and vaporizes rocks and ejects them from the impact site. Credit: Nicolle Rager-Fuller, NSF

The melt will later cool and fall back to the surface. Tektites are cooled impact melt glasses, usually having aerodynamic shapes, that traveled relatively far from the impact site.

By studying the chemical and isotopic compositions of tektites, and reproducing them in the lab in aerodynamic levitation laser heating experiments, we can learn about the conditions of their formation and gain insight in to the violent and ephemeral impact plume.

Our recent paper, Seconds after impact: Insights into the thermal history of impact ejecta from diffusion between lechatelierite and host glass in tektites and experiments presents a new approach to studying tektite formation and evolution.  We used levitation heating experiments to reproduce the textures and diffusion profiles seen in natural tektites.  The experiments allow for estimates of the temperature-time histories of tektites containing lechatelierite.

Back-scattered electron images of levitation experiments heated to 2200 °C for various times. Darker grey regions are lechatelierite (pure silica glass), which diffuse into the surrounding tektite melt over time at high temperature.  These experiments are compared to the diffusion in natural tektites to estimate the temperature and time spent in the impact vapor plume.

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