Historical clue formulations

• High, wispy clouds — 2026-04-05
• Wispy clouds — 2025-12-22
• Wispy streaks in the sky — 2025-06-29
• Streaks overhead — 2024-05-25
• Wispy clouds — 2023-05-30
• Wispy clouds — 2022-12-13
• Wispy clouds — 2022-09-14
• High, wispy clouds — 2017-07-10
• Wispy clouds — 2016-04-27
• Atmospheric features of Mars — 2015-04-17
• High clouds — 2013-03-31
• Mars atmosphere features — 2012-09-09
• They're no rain-makers — 2011-06-03
• Wispy clouds — 2008-05-13
• High clouds — 2005-08-03
• Wispy clouds — 2004-12-02
• Wispy clouds — 1997-09-10
• Sky sight — 1996-11-23