The Willamette Meteorite

The Willamette Meteorite (following from Wikipedia)

 The Willamette Meteorite, originally known as Tomanowos by the Clackamas Chinook Native American tribe, is an iron-nickel meteorite found in the U.S. state of Oregon. It is the largest meteorite in the United States and the sixth largest in the world. There was no impact crater at the discovery site; researchers believe the meteorite landed in what is now Canada or Montana, and was transported as a glacial erratic to the Willamette Valley during the Missoula Floods at the end of the last Ice Age (~13,000 years ago). It has long been held sacred by indigenous peoples of the Willamette Valley,

including the federally recognized Confederated Tribes of the Grand Ronde Community of Oregon (CTGRC). undefined

The meteorite is on display at the American Museum of Natural History in New York City, which acquired it in 1906. Having been seen by an estimated 40 million people over the years, and given its striking appearance, it is among the most famous meteorites. In 2005, the CTGRC sued to have the meteorite returned to their control, ultimately reaching an agreement that gave the tribe access to the meteorite while allowing the museum to keep it as long as they are exhibiting it.

Physical characteristics and formation

Close-up of the meteorite

The Willamette Meteorite weighs about 34,200 pounds (15,500 kg). It is classified as a type III iron meteorite, being composed of over 91% iron and 7.62% nickel, with traces of cobalt and phosphorus. The approximate dimensions of the meteorite are 10 feet (3 m) tall by 6.5 feet (2 m) wide by 4.25 feet (1.3 m) deep. Most iron meteorites like Willamette originated from the differentiated core of planetesimals or asteroids that collided with another object. Willamette has a recrystallized structure with only traces of a medium Widmanstätten pattern; it results from a significant impact-heating event on the parent body. The Willamette Meteorite contains higher concentrations of various metals that are quite rare in Earth’s crust. For example, iridium, one of the least abundant elements in Earth’s crust, is found in the Willamette Meteorite at a concentration of 4.7 ppm, thousands of times more concentrated than in the crust.