Dreams of being in outer space often symbolize feelings of isolation, exploration, or a desire for freedom. In your dream, being stranded with your mother may indicate a sense of reliance on her for comfort and support during uncertain times. The vastness of space could reflect feelings of being overwhelmed or lost in your current situation.

Dropping the object and witnessing it being sucked away could represent a fear of losing something important or a sense of helplessness in controlling certain aspects of your life. Your mother's warning about being careful suggests that there might be external influences or risks in your waking life that you should be cautious of, perhaps related to emotional or familial connections.

Overall, this dream may be urging you to reflect on your current emotional state, your relationship with your mother, and any situations where you feel out of control. Consider what the object you dropped represents to you and how you can gain a sense of grounding in your life.