science

It's a NYT article. The actual subheader was a too long.

A study adds strong evidence to the hypothesis that the deadly rock came from a family of objects that originally formed well beyond the orbit of the planet Jupiter.

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A team led by Mario Fischer-Gödde, a research scientist at the University of Cologne in Germany, has bolstered that case with the help of the rare element ruthenium. Ruthenium is abundant in asteroids but extremely scarce in Earth’s crust, making it a handy bellwether of past impacts by space rocks. The team searched for isotopes of ruthenium in the geological remnants of the Chicxulub impact.