Mysterious sounds discovered in the stratosphere. Researchers have not yet been able to identify all recorded sounds.
Solar-powered balloons could also be used to investigate mysteries beyond Earth. Robotic balloons could fly through the upper atmosphere of Earth's neighboring planet and collect data for research. The balloons themselves were made by the team themselves using cheap materials: "Our balloons are basically huge plastic bags, with some coal dust on the inside to make them dark," says researcher Daniel Bowman.. There are sounds in the Stratosphere that researchers cannot explain.