From the laudation:

“His methodological focus lies in the measurement of noble gas isotope ratios in terrestrial and extraterrestrial minerals and rocks. Using high-precision ⁴⁰Ar–³⁹Ar and ²⁴⁴Pu fission-track thermochronometry on H chondrites that experienced different degrees of metamorphism, he demonstrated that their parent body was heated very rapidly, most likely by the decay of incorporated ²⁶Al, which decayed to ²⁶Mg with a half-life of approximately 0.7 million years and had disappeared from the early Solar System after only a few million years. This evidence that asteroids formed at a very early stage in the history of the Solar System represents a fundamental contribution to reconstructing its evolution.”