Gosses Bluff is thought to be the eroded remnant of an impact crater. Known as Tnorala, it is located in the southern Northern Territory, near the centre of Australia, about 175 km west of Alice Springs and about 212 km to the northeast of Uluru (Ayers Rock). It was named by Ernest Giles in 1872 after Australian explorer William Gosse's brother Henry, who was a member of William's expedition. The original crater is thought to have been formed by the impact of an asteroid or comet approximately 142.5 million years ago, in the earliest Cretaceous, very close to the Jurassic - Cretaceous boundary. The original crater rim has been estimated at about 22 km in diameter, but this has been eroded away. The 5 km diameter, 180 m high crater-like feature, now exposed, is interpreted as the eroded relic of the crater's central uplift. The impact origin of this topographic feature was first proposed in the 1960s, the strongest evidence coming from the abundance of shatter cones. In the past the crater has been the target of petroleum exploration, and two abandoned exploration wells lie near its centre.