Historical clue formulations

• Study of the heavens: Abbr. — 2017-04-09
• "Cosmos" subj. — 2016-11-09
• Sagan's specialty: Abbr. — 2015-04-14
• Subj. for Galileo — 2013-12-15
• Observatory subj. — 2013-03-31
• Sci. branch — 2013-01-16
• Sci. major — 2012-11-29
• Physics dept. offering — 2012-07-13
• Stellar start? — 2012-04-19
• Space science: Abbr. — 2012-01-10
• College sci. class — 2010-09-02
• Observatory subj. — 2010-05-23
• Observatory subj. — 2009-11-26
• Field in which things are looking up?: Abbr. — 2009-02-05
• Study of the heavens: Abbr. — 2008-08-24
• NASA subj. — 2007-08-23
• Space: Prefix — 2007-02-18
• Observatory observer: Abbr. — 2007-01-28
• Heavenly field?: Abbr. — 2007-01-27
• Sci. of the heavens — 2006-07-18
• Carl Sagan's subj. — 2006-02-19
• Science class: Abbr. — 2005-09-17
• Star sci. — 2002-02-10
• Study of the stars: Abbr. — 2002-01-14
• One of the hard sciences: Abbr. — 2000-05-20