Borsippa or ‘Birs Numrud’ is the ruin of a ziggurat about 15 km south of the city of Babylon in Iraq. What remains of the ziggurat is still 47 metre high. It appears to have consisted of six distinct terraces, each 7 metres high. Each dedicated to a different planet, and stained with the colour for each planet.

In ancient times this was the location of the Ezida temple, which was devoted to the god Marduk and in earlier times to the god Nabu.

The south westerly mound, the Birs proper, is probably the most conspicuous and striking ruin in all of Iraq. On a 30 metre hilltop, a pointed mass of vitrified brick rises around 14 metres high. It is split down the centre and surrounded by huge masses of vitrified brick. Single enamelled bricks, most bearing an inscription of Nebuchadrezzar are also found around the site. They are twisted, curled and broken, as if dammaged by great heat.

Many inscribed clay tablets currently housed in the British Museum, were found during the excavation, revealing that Nebuchadrezzar restored the already crumbling site. The mystery here is the intensity of the destruction since vitrified bricks can only be created by heat exceeding 1100 degrees Celcius in open air, which is impossible to achieve using standard means. The only known vitrification in the open has resulted from nuclear explosions or impacts of comets. The latter can be ruled out in the case of Borsippa. The general belief is that lightning caused the vitrification, a theory which has proven to be impossible.

Who or what caused the extreme heat that was able to melt the temple?