1969 – Allende meteorite falls near Pueblito de Allende, Chihuahua, Mexico
. The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 01:05 on February 8, 1969, falling over the Mexican state of Chihuahua. After breaking up in the atmosphere, an extensive search for pieces was conducted and it is often described as "the best-studied meteorite in history." The Allende meteorite is notable for possessing abundant, large calcium-aluminium-rich inclusions (CAIs), which are among the oldest objects formed in the Solar System. The original stone is believed to have been approximately the size of an automobile traveling towards the Earth at more than 10 miles per second. A number of museums launched expeditions to Mexico to collect samples, including the Smithsonian Institution and together they collected hundreds of kilograms of material with CAIs. Allende contains chondrules and CAIs that are estimated to be 4.567 billion years old, the oldest known matter (other carbonaceous chondrites also contain these). This material is 30 million years older than the Earth and 287 million years older than the oldest rock known on Earth, Thus, the Allende meteorite has revealed information about conditions prevailing during the early formation of the Solar System. Carbonaceous chondrites, including Allende, are the most primitive meteorites, and contain the most primitive known matter. They have undergone the least mixing and remelting since the early stages of Solar System formation. Because of this, their age is frequently taken as the "age of the Solar System."