By Greer Darden
If you floated past the ozone and about twelve miles above the Earth’s surface, this is what would start to happen. The air pressure would drop, the conditions would start to get harsher, humidity would be removed and so would all traces of water. Welcome to the stratosphere! Out here there isn’t much to look at, just wide vast empty space. But it’s not about what we can see that counts here, it’s what can’t see. Invisible to the human eye, meet the space bug!
Now these aren’t actually extraterrestrial creepy crawlers that I’m talking about. They are a variety of microorganisms (or microbes) simply found floating, and living in space. Yes that’s right, living organisms found in the stratosphere, an environment where conditions can be very closely related to the conditions on Mars…
Which then brings us to the question: If living bacteria can survive there, then could life survive on Mars too? That’s exactly what Noelle Bryan and her team wanted to find out. As a microbial ecologist, Noelle studies the habits and habitats, as well as the vertical and horizontal movement, of dust and cell particles. She frequently asks questions like, “Once something gets blown into the air how high does it go?” and “Does the amount make a difference?” The main question for one of her recent research projects was whether these “space bugs” are actually living and thriving in the stratosphere, or whether they are simply cells originating here on Earth that are getting blown super high up in the air. By deploying balloons into the stratosphere, Noelle and her team hoped to be able to catch a few of these microbes, bring them back and test them to see if they could find out more. One of the main problems the team had to deal with was the fact that the atmospheric microbe community has no set standards, so it makes it difficult to compare different works. It was very important that the study was clean with the decontamination process so they could properly identify and categorize the different microbes that they found.
With no previous experiment to go off of, Noelle and her team were basically just told to “wing it!”
“After seven balloon trips we ended up collecting about 20 different kinds of microbes” Noelle said. This was a very big accomplishment since they weren’t positive they were going to be able to catch any in the first place.
I watch Noelle as she moves the pipette back and forth, back and forth, each time only transferring a drop of liquid the size of a pea. She is analyzing the DNA sequences of her very own space bugs that she has been collecting and working on for the past five years. By looking specifically at the 16S gene, Noelle is able to identify and classify the various bugs they collected.
In the past, researchers who have discovered these stratospheric microbes have jumped to conclusions, making claims about extraterrestrial life. However, thanks to Noelle’s DNA analysis and identification of the bacteria, we now know that these microbes are some of the same ones found here on Earth, most commonly found in soil and on plant surfaces. To demonstrate this, Noelle holds a culture dish up to my nose and asks me to smell. “This bacteria is the reason why dirt smells…well, like dirt!” she says as I quickly recognized the familiar scent. These kinds of bacteria are known as endospore formers, which means they can aggregate into a small cluster and then spread out again. What was once one small sample on a culture plate can eventually grow and spread into wild patterns.
One would think that this kind of space exploration would require fancy instruments and lots of money. However according to Noelle most of her research only required the use of a basic high quality microscope along with a desiccator chamber which allows you to remove or control the humidity inside of the chamber. Some of the other instruments they used were SEM machines and centrifuges and the whole project was done for less than five thousand dollars. Along with efficiency and accuracy, their goal was to make the project easily repeatable and affordable for other college campuses to try.
Noelle contributes the success of this research project to the bridging of microbe and aerosol science and stresses the importance of collaboration between fields when doing research. For this project they had specialists in several different fields, including physics, engineering, and biology. As the project comes to a close we will soon find out the full end results of all their hard work and time. But until then we now know that when it comes to science, space and bugs, there’s definitely more than meets the eye.
Editorial Note – Edited by Dr. Paige Jarreau