Use 'unearthly' to describe things that feel like they don't belong to this world, suggesting a mysterious origin. The ruins had an unearthly glow, as if illuminated by another realm.
Pro Tip 2/3
Not Always Scary
'Unearthly' can describe something strange without it being frightening, focusing more on its unusual nature. The artist's imagination gave birth to an exhibit filled with unearthly landscapes.
Pro Tip 3/3
Use with Caution
When calling something 'unearthly', be aware it can imply something negative unless paired with a positive adjective. She had an unearthly charm that was both captivating and disconcerting.