From our point of view on Earth, we look up and often see a variety of birds and flying insects above us. Although that form of animal life usually stops at about 10,000 feet, there have been some sightings of bar headed geese as high as 21,000 feet. However, if we go even higher, say about 33,000 feet, which is near the level a jet plane flies, there doesn’t seem to be a whole lot out there. It seems nearly impossible for life to survive due to the thin air, extremely cold temperatures, high levels of UV radiation, and low amounts of moisture. Previously, scientists thought this part of the atmosphere had nothing more than dust and salt particles, but recent studies conducted by NASA have shown otherwise.
Our sky really is alive! It turns out that it is composed of many different forms of bacteria that make up about 20% of the particles found at these high altitudes. In this first in depth study of our earth’s upper troposphere, we find results that are truly startling. It was hypothesized beforehand that if any microbes were found at this level, they would most likely be dead, but this was not the case. In fact, the majority of the bacteria they found were alive!
But how did they get up there? Scientists believe that heavy winds carry up these bacteria along with water vapor, dust, and other particulates from the earth’s crust.
So apart from the apparent evidence that our earth is surrounded by a cloud of bacteria, why should this be of any interest to us?
Believe it or not, these tiny bacteria could actually help scientists better understand weather patterns, such as cloud formations. Their size allows moisture to attach to the bacteria, which then act as a nucleus on which ice crystals may form. This could lead to formation of clouds and perhaps even precipitation.
Future studies of these atmospheric bacteria could lead to insights on how diseases are spread. It is also possible that with these bacteria floating around in our atmosphere, scientists could engineer the bacteria to breakdown harmful greenhouse gases. Of course, this is all still speculation. Bacteria have already taught us so much about our planet, its life, and now its atmosphere and the future looks promising.
Discover more unbelievable facts at “The Science of Ripley’s Believe It or Not!®” at Arizona Science Center through May 4, 2014!