Historical clue formulations

• Unprecedented — 2026-06-22
• What sending someone to Mars would be — 2018-05-21
• Something record-breaking — 2016-11-22
• Something groundbreaking — 2013-11-29
• It hasn't happened before — 2013-10-25
• Something groundbreaking — 2013-08-01
• "This is totally new!" — 2011-12-13
• Something new — 2011-09-08
• Something unprecedented — 2010-04-04
• Something new — 2007-11-06
• Something original — 2004-03-05