Alan Hildebrand
The Canadian scientist who, in 1991, identified the buried Chicxulub crater in Mexico as the impact that ended the age of the dinosaurs.
Key facts
- Born
- 1955
- Nationality
- Canadian
- Field
- Planetary scientist
Alan Russell Hildebrand was a doctoral student at the University of Arizona in the late 1980s when he set out to find the crater left by the impact that Luis and Walter Alvarez had proposed in 1980.
The clues pointed towards the Caribbean. Rocks of the right age in Haiti contained shocked quartz and glassy spherules, and thick layers of jumbled debris suggested a giant tsunami. Hildebrand learned that in the 1970s the geophysicists Glen Penfield and Antonio Camargo, working for the Mexican state oil company, had found a huge circular structure buried beneath the Yucatán Peninsula, centred near the town of Chicxulub, though their finding had attracted little attention.
In 1991 Hildebrand, Penfield, Camargo and colleagues published evidence that this buried ring, about 180 kilometres across, was the impact crater. Samples from old oil wells drilled into it contained shocked quartz and melted rock of exactly the right age, 66 million years. Further studies, including drilling into the crater's peak ring in 2016, have confirmed it.
Hildebrand later moved to the University of Calgary, where he studies fireballs and meteorites in Canada and has helped recover several new falls. He also coordinates reports of fireballs seen across the country.