Historical clue formulations

• Noted cartoon dog — 2026-09-16
• Second-most massive of the solar system's known dwarf planets — 2023-11-23
• It has only one-sixth of the mass of Earth's moon — 2022-11-27
• Dog owned by a talking mouse — 2022-05-04
• Largest object in the Kuiper belt — 2021-08-29
• Classic Disney character who never speaks — 2021-07-02
• Demoted planet — 2020-02-17
• Underworld ruler — 2019-10-18
• Planet demoted to "dwarf planet" in 2006 — 2018-05-14
• Mickey Mouse's dog — 2017-01-11
• Designated dwarf planet since 2006 — 2016-12-07
• Former planet — 2015-08-03
• Recipient of a major downgrade in 2006 — 2014-08-16
• Dwarf planet whose moons include Charon and 12-Down — 2013-11-19
• Demotion victim of 2006 — 2012-08-12
• Ninth planet no more — 2010-04-19
• Mickey Mouse's puppy pal — 2009-08-27
• 2006 neologism meaning "to demote" — 2008-04-20
• A dwarf planet, now — 2008-03-11
• Planet whose name is a Disney character — 2006-06-19
• Astronomical discovery of 1930 — 2004-09-15
• Disney dog — 2003-06-08
• Cartoon canine — 2001-05-13
• Ruler of Hades — 2000-10-11
• Distant planet — 2000-07-17
• It's about 2,100 miles in diameter — 2000-06-09
• 1930 discovery — 1999-10-17
• Disney pooch — 1995-08-31
• Disney dog — 1995-05-10