Cactus Game Design Message Boards

Short answer: No.

Long answer: Based on the ruling regarding face-down cards, a card can only target a face-down card for effect if it specifies that it can target face-down cards or can affect any or all cards in that location.  As was pointed out in later clarification, cards that cannot target any card in that location because they exclude a card or card types (Lost Souls, in this case), cannot target face-down cards.  And while the opponent chooses the card, it is still Astrologers that targets the card for discard.  Face-down artifacts cannot be targeted, so it does not work.