Supposing we launched a very fast dart from the Space Shuttle, pointed in some direction away from any planet, so that it could travel beyond the solar system. What would it be most likely to hit first after traveling outward for a while

Rocks and minerals kind of dust like, that’s really all there is in space.

The mirror formula for curved mirrors is:

where
f is the focal length of the mirror
is the distance of the object from the mirror
is the distance of the image from the mirror

The sign convention that should be used in order to find the correct values is the following:
- : positive if the mirror is concave, negative if the mirror is convex
- : positive if the image is real (located on the same side of the object), negative if it is virtual (located on the opposite side of the mirror)