2021-04-17

NASA announced the discovery of Kepler-186f, the first exoplanet with a radius similar to Earth's discovered in the habitable zone of another star.

An ammonium nitrate explosion occurred at a fertilizer company facility in West, Texas, U.S., killing 15 people and injuring 160 others.

A Palestinian suicide bomber detonated explosives in a restaurant in Tel Aviv, Israel, killing 11 people and injuring 70 others.

The Netherlands and the Isles of Scilly declared peace, having hypothetically been at war for 335 years without a single shot being fired and no casualties incurred.

Metropolitan Police officer Yvonne Fletcher was shot and killed while on duty during a protest outside the Libyan embassy in London, resulting in an 11-day police siege of the building and a breakdown of Libya–United Kingdom relations.

The Khmer Rouge captured Phnom Penh, the capital of the Khmer Republic, ending the Cambodian Civil War and establishing the socialist state of Democratic Kampuchea.

George Lucas began writing a 13-page film treatment that later formed the basis of Star Wars.

Czechoslovak Communist Party chairman Alexander Dubček was deposed.

Sirhan Sirhan was convicted of the assassination of U.S. senator Robert F. Kennedy.

The Peak District was designated the first national park in the United Kingdom.