In 2016, the International Ocean Discovery Program Expedition 364 drilled and analysed 830 m of core from the 66 million year old Chicxulub impact crater’s peak ring. Chicxulub is unique as the only preserved large impact on Earth and the only impact event linked to mass extinction. Key results are that the Chicxulub peak ring is formed from fractured basement rocks that may host a subsurface biosphere. The impactite layer overlying the peak ring in turn provides insight into resurge and tsunami processes, while the Paleogene sediments contain the record of the recovery of life after the mass extinction event. Analyses greatly aided by a public-private partnership on X-ray CT imaging and analysis with Enthought.