There’s unexpected news for people who believe astrobiology is an ivory-tower science with no practical applications. A growing body of research suggests that extremophile organisms living in the upper atmosphere, at the very edge of space, can affect our lives in unexpected ways, even controlling the Earth’s weather.

At a conference of the American Society for Microbiology in May 2011, a team of scientsts led by Alexander Michaud from Montana State University presented results showing that bacteria play a key role in the formation of hailstones, which cause billions of dollars in damage to drops and property every year.

At the same conference, Pierre Amato of Clermont University, France suggested that airborne microbes may play a role in greenhouse gas formation.

Microorganisms such as bacteria, fungi, and viruses may play a role in the formation of rain as well as hail. Microorganisms may catalyze precipitation by acting as nucleation sites for the formation of water droplets and ice crystals. Inorganic materials can serve as nucleation sites but biological materials have been shown to be much more effectiveness. This effectiveness has been shown to be highly species-specific.

Such discoveries are remarkable because, until recently, it was generally assumed that microorganisms were confined to the lower layers of the atmosphere. It is now known that microbes exist in the stratosphere and perhaps much higher, and a growing body of evidence suggests that high-altitude organisms can effect life on Earth.

Efforts are already underway to determine the upper limits of the Earth’s biosphere. In 2011, NASA launched a balloon to 120,000 feet in an attempt to collect such organisms.

Balloon science is limited, however. Balloons go where the winds take them, rather than where researchers want them, and post-flight recovery efforts are not always successful.

In the near future, reusable suborbital spacecraft will provide new capabilities for sampling upper-atmosphere organisms on a regular basis with high reliability. Correlating atmospheric microfauna with the development of weather systems will require a large of flights over an extended period of time. This is the type of repetitive science that can can benefit greatly from the participation of citizen scientists and citizen space explorers.