Watch this video to learn how to make a little planet effect in Photoshop. Go to Image>Image Size and resize the picture making the width and height equal . Don't forget to unmark the "Constrain Proportions" option. Now that you have a squared photo go to Image>Rotate Canvas>180. Go to Filter>Distort>Polar Coordinates and select the option "Rectangular to Polar". Now rotate as you want to and remove any failures.After you select the picture, make sure the sides are alike and that the horizontal line is 100% horizontal as that will minimize failure. You can remove failures with the clone stamp tool and the patch tool.