Scars in a dream usually represent past pain that's healed into memory rather than an open wound -- proof that you got through something difficult. Noticing a new scar can point to resilience you're only now recognizing, while an old one resurfacing may reflect a memory quietly asking to be revisited.
The misfortunes proceeding from Saturn or Mars are mitigated, if their places are protected by Jupiter, being well disposed and in good aspect. - William Lilly (1602.-1681.)