The Hay Plains have become the focus of geoscientists and researchers who believe the largest known asteroid impact structure on Earth lies buried beneath.

Geologist Tony Yeates, originated the view of the Deniliquin multi-ring structure as an impact structure. He visited the area last week as guest of Edward River Council and U3A (University of the Third Age) in Deniliquin.

Mr Yeates told The Riverine Grazier the structure is yet to be further tested by drilling, but is believed to span up to 520 kilometres in diameter.

This is larger than the Vredefort impact structure in South Africa which to date has been considered the world’s largest, and three times bigger than the Chicxulub crater in Mexico which represents the impact that caused the extinction of the dinosaurs.