I just discovered that somehow duplicate complete copies of the Gaia star and PGC galaxy extension databases were installed when I downloaded them in SkySafari Pro 6 back in 2018. The first set is in:
/Library/Application Support/AppStoreContent/com.simulationcurriculum.SkySafari6MacPro/Products/com.simulationcurriculum.SkySafari6MacPro.UCAC5Extension/Contents/GAIAStars2.skydat
/Library/Application Support/AppStoreContent/com.simulationcurriculum.SkySafari6MacPro/Products/com.simulationcurriculum.SkySafari6MacPro.PGCExtension/Contents/PGCGalaxies2.skydat
and the second set is in:
/Users/marklowenthal/Library/Containers/com.simulationcurriculum.SkySafari6MacPro/Data/Library/Application Support/SkySafari 6 Pro//GAIAStars2.skydat
/Users/marklowenthal/Library/Containers/com.simulationcurriculum.SkySafari6MacPro/Data/Library/Application Support/SkySafari 6 Pro//PGCGalaxies2.skydat
Each set is 1.8GB, a not insignificant chunk of disk space. The files have extactly the same sizes and creation time and dates. Do I need both of these? If not, why wasn't the unneeded one automatically purged? Can I delete one of the sets to reclaim some disk space?
Both PGCGalaxies2.skydat files are dated Mar 21, 2018 12:47pm and both GAIAStars2.skydat files are dated Oct 18, 2018 2:48pm.