In September 2014, the Yale Peabody Museum’s Collections Manager for Mineralogy and Meteoritics, Stefan Nicolescu, brought a very rare meteorite – known as NWA 7325 – to the IPCH Digitization Lab for 3D laser scanning. The unique specimen is thought to be the first Mercurian meteorite ever found! Prior to scanning, it spent nine months on display in a special exhibit at the Yale Peabody Museum entitled “From Mercury to Earth? A meteorite like no other”
This meteorite is quite old. Its age has been determined to be 4562.8 ± 0.3 million years! That means the meteorite predates Earth (which boasts an age of ~ 4540 million years) and is only about four to five million years younger than the first solids in our Solar System (estimated to have formed 4567.18 ± 0.5 million years ago)!
After the meteorite was dislodged from its parent body, it is estimated that it spent over 20 million years traveling through the Solar System before eventually falling to Earth. As it fell through the Earth’s atmosphere, the surface of the meteorite melted then solidified, forming a crust. A few thousand years later, in 2012, a meteorite hunter discovered it scattered in 35 pieces. The largest piece was sliced to generate thin sections and bits for analysis before its owner lent it to the Yale Peabody Museum for display. This piece weighs in at 79.2 grams and measures 3 x 3.5 x 4.5 centimeters.
The meteorite is dark green in appearance, with a light green crust. Over time, while resting on the desert floor in Morocco, terrestrial material precipitated onto its surface. This precipitate is manifested as areas of yellow-whitish material consisting of calcium carbonate pigmented by iron oxides and hydroxides.
Upon scientific analysis, a telltale extraterrestrial signature was detected –the presence of meteoritic iron, which is quite rich in nickel. In contrast, terrestrial iron is devoid of nickel. This was an immediate indication that the rock was not formed on Earth! The meteorite is a fully crystalized rock; it is quite similar to terrestrial igneous rocks; however, both its mineral composition and chemical signature are dissimilar to any other known rock. The individual minerals are not incredibly unusual; it is simply that their combination has never before been observed in a rock. If the meteorite is not derived from the planet Mercury, it must be from a part of the asteroid belt (located between Mars and Jupiter) that has not yet been sampled!
The meteorite was digitally acquired via NextEngine triangulation laser scanner in the Digitization Lab at the Yale Institute for the Preservation of Cultural Heritage (IPCH) on a Monday. By Wednesday of the same week, Stefan had a scaled 3D print in hand courtesy of the Yale Center for Engineering, Innovation and Design (CEID).
The primary objective of the process was to create a digital surrogate of the meteorite for applications in packaging, exhibition and education.
Stefan, who was responsible for taking the meteorite back to its owner in Germany, aimed to apply the 3D geometry acquired via scanning for creating stable and sturdy packaging. The 3D print out was used directly to mold clasps to support the meteorite in a custom-made box.
The main goal of creating a high-resolution 3D model was to print a copy of the meteorite in order to keep a tangible, tactile version of it at Yale. Stefan commissioned Michael Anderson, a natural history artist with the Yale Peabody Museum who also mounted the packaging clasps, to paint the 3D print. The result is outstanding!
The meteorite was scanned, post-processed, printed, painted and photographed with contributions and assistance from Chelsea Graham of the Yale IPCH Digitization Lab, Ellen Su formerly of the Yale CEID and Stefan Nicolescu, Jessica Utrup, Michael Anderson and Fred E. Davis of the Yale Peabody Museum.
For more information about NWA 7325’s time at Yale, please see http://news.yale.edu/2013/11/25/mercury-morocco-and-onward-yale-meteorite-s-tale