The galaxy M74 is at a distance of roughly 9 Mpc = 9,000,000 pc.

                                                          -7
   A single HST pixel is 0.05 arcseconds across = 2.4 x 10    radians.


   Q:  How big an area in M74 does a single HST pixel cover?


         h  =  d sin(theta)

                      6                   -7
            =  (9 x 10  pc) * sin(2.4 x 10   rad)


                      6                -7
            =  (9 x 10  pc) * (2.4 x 10    )



            =      2  pc