India's largest confirmed impact structure — a ~2-billion-year-old crater struck by an ultra-rare ureilite meteorite, since eroded into a raised scar.
Dhala, in the Shivpuri district of Madhya Pradesh, is the largest known impact structure in South Asia and one of the oldest known on Earth — roughly 2 billion years old, formed when a meteorite slammed into the surface.
Struck by an ultra-rare meteorite
Dhala is the only impact structure confirmed to have been made by a ureilite. Ureilites are extremely rare meteorites thought to come from differentiated planetesimals and asteroids of the early Solar System — bodies that partly melted and separated into layers, so ureilite material includes rock derived from deep in the parent body’s interior.
Why Earth keeps so few craters
Two things erase Earth’s impact record. First, the atmosphere: NASA estimates that space rocks smaller than about 25 m (~82 ft) mostly burn up on entry, doing little or no damage. Second, time and geology: even the larger strikes — Earth has been hit by thousands of asteroids over 1 km across in its history — leave craters that erosion, tectonics, and volcanism slowly reshape, or erase completely.
A crater turned inside-out
Strangely, Dhala today is a raised patch of terrain, not the circular depression you’d expect of a crater. Around 2 billion years of erosion have stripped away the original crater — rim and all. The high ground at its centre is the central uplift: rock that rebounded upward during the impact and then collapsed, later left standing as the softer surrounding rock wore away. What survives is a deeply eroded remnant, not the crater as it first looked.
As always, if you spot mistakes in my explanation, please correct me. 🙏🏼
References
- Pati, J. K. et al. — research on the Dhala impact structure, Bundelkhand craton
- Geological Survey of India
- NASA — near-Earth object / atmospheric-entry estimates