Violent lightning storms clustered around several of the higher mountains may be due to turbulent ash plumes from volcanic eruptions. The unusually high amount of sulfur dioxide that suddenly appeared in the late 1970 s and has since decreased and stabilized may be further evidence for volcanism. Sulfur dioxide is one of the main gases released during a volcanic eruption. Such a frightening and fascinating world is making scientists eager to return, explore and bring back samples from Venus surface. It may seem like a crazy idea, but exploring planets by balloons may prove to be the way to make on-site measurements, especially with Jupiter, Saturn, Uranus, and Neptune where there is no solid surface to land on.
Titan also have atmospheres capable of supporting a free-floating balloon.
To date only one planet has been explored by balloon. In 1985 the Russian VEGA mission deployed two balloons into Venus s atmosphere at an altitude of 34 miles. Both survived nearly 48 hours and traveled a third of the way around the planet. This confirmed the strong, high altitude winds and also made measurements of temperature and pressure. More importantly, the mission proved that other planets can be explored by balloon.