blue-green bright oval was spotted 20 miles south of Sheridan, WY descending to earthMy wife and I were driving about 20 miles south of Sheridan, WY when we witnessed a bright blue-green oval falling from a west to east direction. The oval was very large in size and lit up the clouds as it passed through the sky. There were parts of the craft falling off as it descended. There was no noise heard from such a large craft.