Perhaps one of the most interesting questions concerning the planets involves Venus. Could Venus have life? With the blistering, nearly 900ºF surface temperature at a crushing atmospheric pressure 92 times Earth’s and carbon dioxide laced with sulfuric acid mist for air it may seem strange to ponder this question. However, high above the surface, around 30 miles up, conditions are more earthlike where life could possibly exist.

The clouds of Venus, when seen through ultraviolet light, have dark streaks. Something in the atmosphere absorbs ultraviolet radiation creating these streaks. It could be particulate matter mixed in the clouds or something dissolved by the sulfuric acid in the atmosphere such as iron chloride. How these particles could get so high into the atmosphere is another mystery since surface winds are so light. Could active volcanoes be the source? The particles could be coated with ring-shaped polymers of eight sulfur atoms, called S8 molecules, which exist in the clouds and are impervious to the corrosive effects of sulfuric acid. If the particles are microbes, they could be impervious to the corrosive effects of sulfuric acid. This theory is so inspiring that it has made its way into a science fiction novel by Ben Bova called “Venus” where the clouds thrive with bacteria. The only way to find out if this is true is to go to Venus and sample the clouds where the dark streaks are located. While Venus has been ignored by NASA since the early 1990s, there are plans to go back thanks to Russia.

Venera-D is a Venus mission that the Russian Space Agency ROSCOSMOS has been working on that would descend into the thick clouds and place a lander on the surface. There are plans to add a balloon, or better yet, an unmanned aerial vehicle (UAV) which would sail through the clouds for an extended period of time. If the UAV is approved, it would take meteorological measurements to try to determine why the atmosphere rotates so fast compared to the surface. The UAV would be solar powered as it would be sunny enough at that altitude, which would allow it to stay aloft for at least one Earth year. It would glide freely into the night side at which point it would descend lower, but then would power back up in the daylight and climb to higher altitudes. With enough solar power, it could run on electric propellers for a long time. This would make it possible for it to move from region to region, cloud to cloud mass, into clearings and regions where the ultraviolet absorbing particles may be. An UAV allows better maneuverability than a balloon and would be longer lasting allowing better sampling of the atmosphere. It would have added buoyancy from either hydrogen or helium gas.

Venera-D has been in the works for awhile and was hampered by the loss of Phobos-Grunt along with technical and budget issues. The original plan of a lander lasting for a few days to a few weeks has proven to be too challenging and costly to design, but a Venus aerial vehicle is more realistic and may even last longer than a Venus year of 225 days. There are hopes of finally returning to this nearly forgotten and still mysterious world, but Venera-D would not fly before 2025. It would be the most bizarre discovery to find life at Venus instead of Mars!