/usr/share/stellarium/skycultures/mongolian/ is in stellarium-data 0.14.3-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/stellarium/skycultures/mongolian/constellation_names.eng.fab
/usr/share/stellarium/skycultures/mongolian/constellation_names.fr.fab
/usr/share/stellarium/skycultures/mongolian/constellations_boundaries.dat
/usr/share/stellarium/skycultures/mongolian/constellationship.fab
/usr/share/stellarium/skycultures/mongolian/description.bn.utf8
/usr/share/stellarium/skycultures/mongolian/description.en.utf8
/usr/share/stellarium/skycultures/mongolian/description.fr.utf8
/usr/share/stellarium/skycultures/mongolian/description.hu.utf8
/usr/share/stellarium/skycultures/mongolian/description.uk.utf8
/usr/share/stellarium/skycultures/mongolian/doloon_burkhan.png
/usr/share/stellarium/skycultures/mongolian/info.ini
/usr/share/stellarium/skycultures/mongolian/planet_names.fab
/usr/share/stellarium/skycultures/mongolian/star_names.fab