In the flashback, there is an external panning shot of Enterprise swooping by the proving ground from the previous episode. The debris from the exploded moon would not be static even days later. Conservation of momentum and gravity dictates it would form a cloud of chaotically moving rocks of varying size.
When Archer and Trip are discussing the Xindi's subspace vortices a PC mouse cursor can be seen on the master display showing the location of the red giant star.