We now finally know from where the asteroid that killed dinosaurs and about 76 per cent of species on earth came from. A groundbreaking study has traced the asteroid that caused the Chicxulub impact 66 million years ago to the cold, dark regions of the outer Solar System.
They say that the asteroid was from a region of the Solar System out past the orbit of Jupiter, the cold, dark outer limits, far from the Sun’s light and warmth.
The Chicxulub impact marked the end of the Cretaceous period, leading to the mass extinction of about 76% of Earth’s species, including non-avian dinosaurs. The asteroid, estimated to be about 10 kilometres (6 miles) in diameter, struck what is now the Yucatán Peninsula, creating a massive crater and initiating a global extinction event.
UNRAVELING THE ASTEROID’S ORIGINS
To uncover the asteroid’s origin, researchers analyzed the boundary layer from the impact site, searching for signs of extraterrestrial materials. This layer contains elevated levels of platinum-group elements like iridium, ruthenium, and osmium, which are rare on Earth but common in meteorites.
ROLE OF RUTHENIUM ISOTOPES
Led by geochemist Mario Fischer-Gödde from the University of Cologne, the team focused on ruthenium isotopes to differentiate between extraterrestrial and terrestrial sources. They compared isotopic ratios in the Cretaceous-Palaeogene boundary layer with those from meteorites and other impact sites.
CARBONACEOUS CHONDRITES IDENTIFIED
The analysis revealed that the ruthenium in the boundary layer matched that found in carbonaceous chondrites, a rare type of asteroid rich in carbon from the outer Solar System. This finding rules out comets and confirms the asteroid’s origins beyond Jupiter’s orbit.
COMPARATIVE ANALYSIS
The study also examined isotopes from other impacts and ancient spherule layers. These comparisons showed that while siliceous asteroids (common closer to the Sun) and ancient carbonaceous spherules were different, the Chicxulub impactor’s characteristics aligned with carbonaceous chondrites.
IMPLICATIONS FOR SOLAR SYSTEM DYNAMICS
This research suggests that although Jupiter typically traps outer Solar System objects, some can still penetrate inward. The Chicxulub impactor was an exception, highlighting the dynamic and occasionally unpredictable nature of Solar System interactions.
WHY DID THE ASTEROID TARGET DINOSAURS?
While the exact reason why this particular asteroid targeted Earth remains unknown, the study sheds light on the asteroid’s origins and the broader context of cosmic impacts. The findings enhance our understanding of the Solar System’s history and its influence on Earth.
FUTURE RESEARCH DIRECTIONS
Future studies may explore the frequency and impact of such large asteroids and their potential to cause significant planetary changes. Understanding the behaviour of Solar System bodies could provide insights into mitigating future cosmic threats.