Historical clue formulations

• It was discovered by the Curies — 2026-05-13
• Element discovered by Marie and Pierre Curie — 2026-03-30
• 1898 chemistry discovery — 2020-05-01
• Element discovered by Marie and Pierre Curie — 2020-04-13
• Subject of Marie Curie's isolation — 2018-08-31
• Curie discovery — 2015-07-15
• Bygone component in luminous paint — 2015-06-17
• Alpha particle emitter — 2005-11-18
• Discovery of 1898 — 2003-12-13