1" Henbury Iron Meteorite (12g) - Australia

The Henbury Meteorite

Henbury is the name given to an iron (IIIAB) meteorite that fell about 4,700 years ago. It created about a dozen craters in its strewn field. Both the fall itself and the field were known to Aboriginal peoples, and several stories and traditions contain information about them.

Europeans knew about the craters as early as 1899, but they were not officially found until an expedition to the area in 1931. About 800 pieces, both fragments and shrapnel, were collected in this first expedition, and since its discovery over 2 metric tons of material have been recovered. The Northern Territory government made the impact site into a Conservation Reserve park, where it remains a popular tourist destination.

About Iron Meteorites

Iron type meteorites are composed primarily of iron and nickel, and are the remnants of differential cores torn apart at the beginning of the solar system. These metallic meteorites are often the easiest to identify after millions of years post-impact because they are quite different from terrestrial material, especially when it comes to their mass-to-surface area ratio. They are exceptionally heavy for their size since iron is a high-density metal: this is also why the Earth's core is nickel-iron. As planets form, the densest metals form gravitational centers, bringing more and more material into their gravitational pull. In the solar system's rocky planets, these dense materials are most often nickel and iron.

Most iron meteorites have distinctive, geometric patterns called Widmanstätten patterns, which become visible when the meteorite is cut and acid etched. These patterns are criss-crossing bands of the iron-nickel alloys kamacite and taenite that slowly crystalized as the core of the meteorites' parent bodies slowly cooled. Such large alloy crystallizations for mover millions of years and do not occur naturally on Earth, further proving that iron meteorites come from extraterrestrial bodies.