The Willamette Meteorite in structure is a metallic iron meteorite, is the largest meteorite found in the United States, and the sixth largest in the world. No impact crater was preserved at the discovery site; it is possible that the meteorite landed in what is now Canada and was transported to where it was found by by glacial/flood deposits during the Missoula Ice Age Floods.
Metallic iron meteorites are a relatively rare kind of meteorite. They comprise a class of about 600 out of a total of 25,000 meteorites so far found on the Earth's surface.
The microscopic structure of the meteorite is unusually complicated and suggests a unique set of events subsequent to its original formation, yet to be fully analyzed. What we do know about formation of the Willamette Meteorite can be best summarized in four stages.
Stage 1: Billions of years ago in the early history of our solar system, a planet which orbited the Sun was shattered. Fragments of this shattered planet likely included the Willamette Meteorite, which probably represents the iron-nickel core of this planet. The original break-up of the planet and cooling of the resulting fragments is evident in the microscopic structure of the meteorite.
Stage 2: During its long sojourn in space, the Willamette Meteorite sustained at least two subsequent shocks. These were high-energy impacts likely due to collisions among planetary fragments, which caused re-heating and re-crystallization observable in the micro-structure of the meteorite. One of these shocks may have been responsible for knocking the Willamette Meteorite into a collision course with the Earth.
Stage 3: Perhaps a billion years later, the meteorite penetrated the Earth's atmosphere and collided with the Earth's surface at supersonic speed. Unfortunately, we cannot directly see any remnants of this impact stage because of long-term weathering of the meteorite after its impact.
Stage 4: The final form of the Willamette Meteorite resulted from the long-term exposure and weathering in the humid Northwest region. The large cavities on the exposed flat side of the meteorite formed not in space but on Earth during this weathering period. This occurred from interaction of rainwater with iron sulfide deposits in the meteorite, producing weak sulfuric acid. The etching by this acid, an extremely slow process, dissolved the metal and produced the cavities that you see now.
The Willamette Meteorite was discovered in the Willamette Valley of Oregon, near the modern city of West Linn. Although apparently known to Native Americans, its modern discovery was made by settler Ellis Hughes in 1902. At this time the land was owned by the Oregon Iron and Steel Company. Hughes recognised the meteorite's significance, and in an attempt to claim ownership, secretly moved it to his own land. This involved 90 days of hard work to cover the 3/4 mile distance. The move was discovered and after a lawsuit, the Oregon Iron and Steel Company was recognized as the legal owner.
In 1905 the meteorite was purchased by Mrs. William E. Dodge for $26,000. After being displayed at the Lewis and Clark Centennial Exposition, it was donated to the American Museum of Natural History in New York City where it is now on display.
The meteorite was an object venerated by the Native American tribe inhabiting the area where it was found. The Confederated Tribes of the Grand Ronde Community of Oregon, a confederation of Native American tribes, used the meteorite, which they call Tomanowos, in an annual ceremony, and have requested that it be returned. The tribes reached an agreement with the museum in 2000. This states that tribal members may conduct a private ceremony around the meteorite once a year, and that ownership will be transferred to them should the museum stop using it for display.
In response to a student's request in 2007, Representative John Lim introduced a resolution that would demand that the museum return the meteorite to Oregon. The tribes said they were not consulted, they did not support the resolution, and were content with the current arrangement with the museum.
A 30-pound piece of the meteorite that had been traded to an individual for a Mars meteorite was planned to be auctioned in October 2007, which led to claims of insensitivity by the Clackamas Indians. The meterorite section did not bring the price expected, however, and it was withdrawn from sale.
A 4.5-ounce, 7.5-inch piece of the meteorite purchased in a 2006 auction is on display at the Evergreen Aviation & Space Museum in McMinnville, Oregon.
A replica stands near the Willamette Methodist Church in West Linn, Oregon. While this replica of the meteorite is in Eugene, Oregon, outside the University of Oregon Museum of Natural and Cultural History on the University of Oregon campus.
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