a good concept but the image seems a more than a bit underexpose
In order to fix the underexposure, a simple levels adjustment would work.
See picture with a copy of the histogram.
By adjusting the white 'triangle' so that it is near the edge of the actual histogram, you bring back the underexposed bits.
Alternatively, you can set your camera to manual, set the correct exposure for the sky (spot meter and adjust aperture/ shutter speed) and then throw the horseshoes....
FINALLY! Objects in the air! Not the best image... but golly! Just so good to see someone following the challenge description! Kudos to you! Wish it were brighter... and less grainy... but golly! Just so good to see!