it is thought to be the remains of a huge meteorite strike. its centre is in the northern territory, about halfway between uluru (ayers rock) and mount conner. the crater is about 600 km (370 mi) in diameter. there is a wider ring 2,000 kilometres (1,200 mi) in diameter which may be related to the impact. if it is confirmed, mapcis would be the largest impact structure on earth. it is not confirmed at present.