A recent study has unveiled intriguing new details about the asteroid that caused the extinction of the dinosaurs 66 million years ago. Known as the Chicxulub impactor, this asteroid was an unusual type, having formed beyond the orbit of Jupiter, unlike most other asteroids that have impacted Earth.

Researchers examined the chemical makeup of five other asteroid impactors that struck Earth over the past 540 million years, comparing their composition to that of the Chicxulub impactor. Their findings revealed that the dinosaur-killing asteroid contained a mixture of ruthenium, a marker identifying it as a carbonaceous asteroid. These types of asteroids are known to form in the outer solar system, specifically beyond Jupiter’s orbit.

Conversely, the other five asteroid impactors contained a different isotope of ruthenium, indicating they were siliceous asteroids, which typically originate from the inner solar system. These siliceous asteroids are associated with the asteroid belt located between the orbits of Mars and Jupiter.

Astronomers studying the formation and evolution of our solar system have suggested that early in the system’s history, Jupiter began migrating closer to the Sun. This phenomenon explains why many solar systems have gas giant planets orbiting close to their stars, even though such planets couldn’t have formed in those locations. Jupiter’s inward migration was eventually halted and reversed by the gravitational forces of Saturn, Neptune, Uranus, and possibly an additional ice giant that was either ejected from the solar system or moved deep into the Kuiper Belt, where it remains undiscovered.

The asteroid belt, composed of inner-solar system rubble that never formed into planets, is located between Mars and Jupiter, where Jupiter’s immense gravity collected it. However, the origins of carbonaceous asteroids, such as the Chicxulub impactor, remain a mystery. Scientists are still trying to understand why these asteroids formed in the outer solar system and how one ended up becoming the dinosaur-killing Chicxulub impactor.

Dr. David Kring, principal scientist at the Lunar and Planetary Institute of the Universities Space Research Association and an expert on the Chicxulub impact, praised the study as “an outstanding application of a new analytical technique.” He emphasized the importance of identifying the type of impactor, stating, “Identifying the type of impactor is important because it helps us evaluate the frequency of such impacts in the geologic past and the hazards of such impacts in the planet’s future.”

Source: The Times, quoting Dr. David Kring, principal scientist at the Lunar and Planetary Institute of the Universities Space Research Association.