Chondritic Meteorite NWA 869

Above: The front of the specimen card. "...Like drops of fiery rain" ~ H.C. Sorby, English Geologist Before the Sun, the solar system was a chaotic swirl of dust and ice. 4.5 billion years later, there are planets, moons, and even life. The journey is a long one that has been difficult to understand. The most important clues we have come from stones nearly as old as the solar system itself: chondritic meteorites. Stony meteorites are classified into two categories, chondrites and achondrites. Chondrites, known for their inclusion of small grains called chondrules, are meteorites that have not undergone internal melting or differentiation since their formation. This means that the material within the meteorites dates back 4.5 billion years, to the birth of the solar system as we know it. Above: A selection of NWA 869 specimens, each like a drop of firey rain. This specimen is a complete chondritic meteorite, specifically meteorite NWA 869. NWA 869 was discovered in Northwest Africa in 2000. Over two metric tons of material from this meteorite have been found so far, with sizes ranging from pebble-sized to enormous chunks weighing more than 40 pounds. The specimen is housed in an acrylic jar that is encased within a glass-topped riker display box. The box measures 4 1/2" x 3 1/2". A small information card is also included, which serves as the certificate of authenticity. Please Note: The specimens vary in size and shape. Product images are representative samples. About Chondritic Meteorites Planets have enough mass to cause significant melting and separation of geologic material. This makes it difficult to learn how they were formed, as their initial state is lost to time. Chondrites, however, have remained relatively untouched. Their geologic structure is a relic from the early solar system and clarifies the past of larger, more complex bodies as well. Before the planets formed, the solar system was a mix of dust, grains, and ice that orbited the protosun in a disk shape. Over time, this material smashed together, slowly forming planets and asteroids. While the planets grew and changed, asteroids floated around the solar system for billions of years, only occasionally colliding with other objects. Eventually, some asteroids approached Earth, impacting and becoming meteorites. Chondrites can be identified by the presence of small round grains called chondrules. These beads vary in size but tend to be around a millimeter in diameter. Chondrules are made of silicate minerals and can be glassy or crystalline. It is suggested that they were created by the flash heating and rapid cooling of dust in the early solar system and that the chondrules then gradually accreted together. These tiny objects are the oldest solid matter in the solar system and are the building blocks of planets. Further Reading McSween, Harry Y. “Chondritic Meteorites and the Formation of Planets: Leftover Raw Materials from the Beginning of the Solar System Provide Insights into the Way the Planets Were Assembled.” American Scientist, vol. 77, no. 2, 1989, pp. 146–153. Sorby, H.C, “On the structure and origin of meteorites”, Nature, vol 15, no. 388, 1877, pp. 405–498. Connelly, James N., et al. “The Absolute Chronology and Thermal Processing of Solids in the Solar Protoplanetary Disk.” Science, vol. 338, no. 6107, 2012, pp. 651–655. Above: The back of the specimen card.