Natural glass

In June of 1908, near the Tunguska river in Evenka, Siberia, 60 to 80 million trees over 2000 square km were flattened overnight by what was probably a huge explosion, referred to by scientists as the Tunguska Event. There were very few witnesses, and the event has never quite been explained (though most now assume that it was a porous meteor exploding in mid-air causing an enormous explosion known as an airburst). For some reason, very few people have heard of this.

Anyway, this morning I read this BBC report, claiming that a jewel in one of Tutankhamen's necklaces was actually glass that was older than the earlist Egyptian civilization. Now it seems that Tut's necklace was created from chunks of glass that have been found scattered over a remote region in Sahara.

The thing is, glass forms naturally in nature when silicate sand (what glass is made from) is exposed to extremely high temperatures. For instance, atomic bomb tests in deserts have produced a thin layer of glass on the ground. The most common creator of natural glass is a lightning strike, producing glass formations known as fulgurites. (I actually found what I'm pretty sure now was a fulgurite in a dune on a beach in Southern California in 1995. It was sandy, brownish-green, root-shaped, hollow and very brittle. I regret not trying to bring it home.)

Whatever created that glass in Sahara was way bigger and more intense than Hiroshima. So scientists now think that they have found evidence for at least two more Tunguska-like events. One in Sahara, which created the glassy rocks there, which went into Tutankhamen's necklace, and one in Southeast Asia (the place is not specified). Isn't that just tremendously interesting?