The craters discovered recently near Dukhan, 90km west of Doha, are of unusual shape, according to Qatari astronomical observer and active member of Qatar Scientific Club Sheikh Salman bin Jabor Al Thani. Images of these craters, believed to have been formed following meteor impact nearly seven decades ago, were presented by Sheik Salman at Doha Scientific Club on Sunday. The craters discovered have an upward curve rather than a depression as in normal craters. The soft nature of the sand in the site can be accounted for this shape.