/usr/share/stellarium/landscapes/neptune/ is in stellarium-data 0.14.3-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/stellarium/landscapes/neptune/description.ar.utf8
/usr/share/stellarium/landscapes/neptune/description.be.utf8
/usr/share/stellarium/landscapes/neptune/description.bn.utf8
/usr/share/stellarium/landscapes/neptune/description.en.utf8
/usr/share/stellarium/landscapes/neptune/description.fr.utf8
/usr/share/stellarium/landscapes/neptune/description.hu.utf8
/usr/share/stellarium/landscapes/neptune/description.pt_BR.utf8
/usr/share/stellarium/landscapes/neptune/description.ru.utf8
/usr/share/stellarium/landscapes/neptune/description.uk.utf8
/usr/share/stellarium/landscapes/neptune/landscape.ini
/usr/share/stellarium/landscapes/neptune/neptune-256.png