A solar balloon is a black balloon that is filled with air. Due to the dark color of the balloon, it heats up in the sun. This causes the air present inside the solar balloon to expand and reduce in density compared with the surrounding air. As such, the balloon functions like a hot air balloon. Usage at the moment is currently restricted to the toy market, although it has been proposed that it be used in the investigation of planet Mars.

Solarballon | Khí cầu mặt trời