Earth has been constantly bombarded since its formation by asteroids, comets, and meteorites. However, scientists are not sure about the type of impacts and their origin, i.e. whether they come from the solar system or beyond.
Scientists from the University of Allahabad in India and Switzerland recently published the discovery of the past, which is the oldest iteral university impact on Earth.
Lead scientist Aryavarth Anand, from Bern, Switzerland, identified the impactor type from chemical traces using chromium-isotope systematics and Prof. JK Pati and his group also used osmium isotope data published in 2017.
The Dhala impact structure, about 11 km in diameter, is the largest confirmed impact structure ever reported between the Mediterranean and South-East Asia and was discovered in 2005 by Prof. Confirmed by JK Pati.
According to scientists, the discovery of an impactor type of crustal structure is set to revolutionize our understanding of impact events on Earth and the early history of the Solar System.
The discovery has now been published in the May 2023 issue of ‘Meteoritics and Planetary Science’, the prestigious journal of the Meteorological Society of America.
Uralites are a unique class of primitive achondrite that comprise only a small fraction of all known meteorites on Earth. These stony meteorites are composed of small amounts (less than 10%) of interstitial material, including olivine, pyroxene, carbon (diamond and other polymorphs), metal sulfides, and some fine silicates. A 1-km-diameter urilite meteorite impacted granitoid rocks of the Bundelkhand craton at extraordinary speeds (>15 km/s), which is now believed to have formed the ‘Dhala impact structure’,” shared Prof Pati.
Although common chondrites (the most abundant meteorites) account for 85% of Earth’s extant meteorite collection, the identification of the projectile type of the Dhala impact structure argues for a diverse source of material that collided with Earth.
The discovery marked a pivotal moment in impact cratering research and planetary science worldwide.
Further investigations into the Dhala impact structure are already underway, as scientists are eager to find out more details about the nature of this rare urilite meteorite, said Anuj Kumar Singh, Shyama Prasad Mukherjee Fellow (Department of Earth and Planetary Sciences, AU), one of the co-authors of the published paper.
Accordingly, a detailed study of this impact event can provide a deeper understanding of the role of meteorites in delivering organic compounds and water to Earth, which play an important role in the development of life on our planet. The discovery also has significant implications for the study of impact structures on other solid planets, offering valuable insights into the geological evolution of the universe, he added.