Scientists say an iron knife buried with King Tut is truly out of this world.
The knife was made with iron that came from a meteorite, according to an article in the journal Meteoritics and Planetary Science published online last month.
The dagger in question was one of two found in the wrapping of King Tutankhamun's mummified body in 1925 by archaeologist Howard Carter. The first knife has a blade of gold, while the iron dagger has a gold handle, rock crystal pommel and jackal-decorated sheath.
The iron knife has puzzled researchers for 91 years, partially because ironwork was rare in ancient Egypt. Despite being more than 3,300 years old, the iron dagger shows no signs of rust, according to The Guardian.
Researchers from Milan Polytechnic, Pisa University, and the Egyptian Museum in Cairo studied the metal makeup of the iron knife using non-invasive, portable X-ray fluorescence spectrometry.
"Meteoric iron is clearly indicated by the presence of a high percentages of nickel," lead researcher Daniela Comelli of Milan Polytechnic told The Telegraph. "The nickel and cobalt ratio in the dagger blade is consistent with that of iron meteorites that have preserved the primitive chondritic ratio during planetary differentiation in the early solar system."
The researchers said they identified the exact meteorite that was the source of metal for the blade.
Comeli said her team examined all meteorites found within a radius of 2,000 kilometers from the Red Sea. That narrowed the possibilities to 20 iron meteorites. Only one of those had levels of nickel and cobalt similar to Tut’s blade: a meteorite found near Mersa Matruh, Egypt, 16 years ago.
The finding suggests that the ancient Egyptians were aware in the 13th century B.C., about 2,000 years before Western culture, that rare chunks of iron fell from the sky.