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Typical analyses include investigation of the minerals that make up the meteorite, their relative locations, orientations, and chemical compositions; analysis of isotope ratios; and radiometric dating. These techniques are used to determine the age, formation process, and subsequent history of the material forming the meteorite.
Fall – a meteorite that was seen while it fell to Earth and found. Find – a meteorite that was found without seeing it fall. Fossil meteorite – a meteorite that was buried under layers of sediment before the start of the Quaternary period. Some or all of the original cosmic material has been replaced by diagenetic minerals.
A "meteorite fall", also called an "observed fall", is a meteorite collected after its arrival was observed by people or automated devices. Any other meteorite is called a "meteorite find". [43] [44] There are more than 1,100 documented falls listed in widely used databases, [45] [46] [47] most of which have specimens in modern collections.
A meteor, known colloquially as a shooting star or falling star, is the visible passage of a glowing meteoroid, micrometeoroid, comet or asteroid through Earth's atmosphere, after being heated to incandescence by collisions with air molecules in the upper atmosphere, [11] [23] [24] creating a streak of light via its rapid motion and sometimes ...
Space weathering is the type of weathering that occurs to any object exposed to the harsh environment of outer space. Bodies without atmospheres (including the Moon , Mercury , the asteroids , comets , and most of the moons of other planets) take on many weathering processes:
A chondrite / ˈ k ɒ n d r aɪ t / is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. [a] [1] They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids.
In gaps between the kamacite and taenite lamellae, a fine-grained mixture called plessite is often found. An iron nickel phosphide, schreibersite, is present in most nickel-iron meteorites, as well as an iron-nickel-cobalt carbide, cohenite. Graphite and troilite occur in rounded nodules up to several cm in size. [2]
Meteorites composed of 6 wt% or less nickel are often referred to as hexahedrites due to the crystal structure of kamacite being isometric and causing the meteorite to be cubic. Likewise if the meteorite is dominated by the face centered taenite it is called an octahedrite as kamacite will exsolve from the octahedral crystal boundaries of ...