Solving the riddle of the desert glass
It was in 1932 that British explorers in Model-A Fords first visited this area of western Egypt, where they discovered a mysterious yellow-green glass scattered across the surface. Ever since, Libyan Desert Glass has fascinated scientists, who have dreamed up all sorts of ideas about how it could have formed. It’s too silicarich to be volcanic. In some ways it resembles the tektites generated by the high pressures associated with asteroid impacts. That observation is the starting point of a scientific debate that became the subject of the documentary filmed for National Geographic and BBC.
The mysterious glass “yellowgreen jewels that have smooth surfaces sculpted by the incessant wind.”
(photo by Mark Boslough)
I was chosen to participate in the role of a dissenter from the preferred explanation that the glass was formed by direct shock-melting by a crater-forming asteroid impact. I had stumbled into the debate by accident in 1996, when I attended a conference on the subject of the 1908 explosion of an asteroid or comet that knocked down nearly a thousand square miles of trees in Siberia. I stayed an extra day to attend a meeting about the desert glass, where I argued that similar — but larger — atmospheric explosions could create fireballs that would be large and hot enough to fuse surface materials to glass, much like the first atomic explosion generated green glass at the Trinity site in 1945.
King Tut connection
(photo by Mark Boslough)
Shortly after that workshop, one of the Italian organizers made a discovery that raised public interest in the subject. Vincenzo de Michele visited the Egyptian Museum in Cairo, and noticed that one of King Tutankhamun’s jeweled breastplates contained a carved scarab that looked suspiciously like a piece of the glass. A simple optical measurement confirmed the match in 1998. The connection of a catastrophic explosion with the treasures of ancient Egypt became a sure-fire formula for a documentary.
Last December, when I was first asked by the producer to be interviewed, I was a little skeptical. After all, television is known more for sensationalism than for scientific accuracy, and the King Tut connection had fueled pseudoscientific speculation on the web. One website even presents fanciful “Evidence for Ancient Atomic War,” making the case that Egyptians had detonated nuclear weapons (but ignoring the fact that the glass is 29 million years old). Did I want to be part of this?
Fortunately, I was assured by other scientists that this would be a legitimate documentary that would focus on natural explanations for this enigmatic glass. In February, I found myself in Cairo with Dr. de Michele, getting a firsthand look at King Tut’s glass scarab and preparing for nine days in the desert.
A quarterly research and development magazine.
