Gary sent in the link https://www.sciencealert.com/strange-yellow-glass-in-african-desert-traced-back-to-extraterrestrial-impact … meteor impacts are becoming as common as kippers on a breakfast plate. In the desert zone that straddles the border between Egypt and Libya there is an area that sports yellow glass like fragments. Some of them can be quite big. Tutankhamun had the same glass, in the form of a pendant, in his tomb. It has obviously intrigued a lot of people when looking at exhibitions of finds from his tomb. Hence, the current research. Mainstream had suggested it was a kind of fulgarite – produced by lightning – striking sand. Others that it was produced by a meteor exploding in the atmosphere. Still others thought it had a terrestrial origin. The yellow comes from silicate, for example – sand. New research is said to show it was derived from a meteor impact hitting the surface of the earth. In this instance, a body of sand and soil. It was initially estimated at 29 million years ago. This was deemed unlikely as the environment of North Africa was quite different that long ago. It is therefore somewhat younger but its age will depend on what date can be extracted from the crater. At the moment, they have not found a crater. It is assumed it is buried under the sand. However, an explosion low in the atmosphere, not too far from the surface of the earth, may not have left a crater. We shall see in due course.