On 26 April 1986, the Chernobyl Disaster occured, releasing immense quantities of radioactive material for days before it could be contained. It is considered the worst nuclear power plant accident in history: the contamination spread across the former USSR territories and reached even Western Europe. The radiation resulted in lasting pollution of the areas and had a massive impact on the health of people. We investigated this event and wrote blog posts sharing how the memory of this event is contested and remembered: We reveal personal experiences of liquidators, look at today’s perception of the accident in Ukraine and Belarus and set up a Tweetology-Timeline of the nuclear catastrophe and its aftermath.