Scientists reveal exciting details about the origin of the dinosaur-killing asteroid beyond Jupiter

Washington, DC – An intense debate about the cosmic rock that wiped out the dinosaurs has scientist for decades, but a new study has brought to light some important and surprising data about the impact body's formation history.

Researchers whose findings were published Thursday in the journal Science used an innovative technique to prove that the apocalyptic culprit that slammed into Earth's surface 66 million years ago and caused the recent mass extinction originated beyond the orbit of Jupiter.

They also refute the idea that it was a comet.

The new findings about the suspected asteroid that hit Chicxulub on what is now Mexico's Yucatan Peninsula could improve our understanding of celestial objects that have impacted our planet.

“Now with all this knowledge we can say that this asteroid originally formed beyond Jupiter,” said Mario Fischer-Godde, lead author of the study and geochemist at the University of Cologne.

The conclusions are particularly remarkable considering how rarely this type of asteroid collides with Earth.

Such information could prove useful in assessing future threats or in determining how water got to our planet, Fischer-Godde said.

The new findings are based on the analysis of sediment samples from the period between the Cretaceous and Paleogene, the time of the devastating asteroid impact.

Researchers have measured isotopes of the element ruthenium, which is not uncommon on asteroids but extremely rare on Earth.

By examining the deposits in several geological layers that mark the debris from the Chicxulub impact, they were able to be sure that the ruthenium they studied came “100 percent from this asteroid.”

“Our laboratory in Cologne is one of the few laboratories that can carry out such measurements,” and it was the first time that such examination techniques had been applied to layers of impact debris, said Fischer-Godde.

Ruthenium isotopes can be used to distinguish two main groups of asteroids: C-type or carbonaceous asteroids, which formed in the outer solar system, and S-type silicate asteroids from the inner solar system, which is closer to the sun.

The study confirms that the asteroid that triggered a mega-earthquake, brought about a global winter, and wiped out the dinosaurs and most other life was a C-type asteroid that formed beyond Jupiter.

Studies from two decades ago had already made such an assumption, but with far less certainty.

The conclusions are remarkable because most meteorites – fragments of asteroids that fall to Earth – are of type S, as Fischer-Godde emphasized.

But does this mean that the Chicxulub impactor originated beyond Jupiter and was heading directly toward our planet? Not necessarily.

“We can't really be sure where the asteroid was hiding before it hit Earth,” Fischer-Godde said, adding that after it formed, it may have made a stopover in the asteroid belt between Mars and Jupiter, where most meteorites form.

The study also rejects the idea that the destructive impactor could have been a comet, a mixture of icy rocks from the outermost edge of the solar system.

Such a hypothesis was put forward in 2021 in a widely acclaimed study based on statistical simulations.

Sample analyses now show that the composition of the celestial body differed significantly from a subgroup of meteorites believed to have been comets in the past. It is therefore “unlikely” that the impact object in question was a comet, said Fischer-Godde.

The geochemist made two suggestions for further benefit from his findings.

He is convinced that a more accurate description of the nature of the asteroids that have hit the Earth since its formation about 4.5 billion years ago could help solve the mystery of the origin of water on our planet.

Scientists believe that water may have been brought to Earth by asteroids, most likely C-type asteroids, like the one that hit Earth 66 million years ago, although these are rarer.

By studying asteroids from the past, humanity can also prepare for the future, said Fischer-Godde.

“If we find that previous mass extinction events could also be associated with C-type asteroid impacts, then … we have to be very cautious if a C-type asteroid ever orbits the Earth,” he said, “because it could be the last one we observe.”