When I was growing up, National Geographic was the ultimate symbol of adventure and exploration, from the glossy magazine with the bold yellow border to the clarion call of the theme song. I yearned to escape my “normal” life and be part of that big wild world! That why I’m thrilled to announce that I’ve been selected for a National Geographic Explorer award to explore life in the night sky!
Exploring the night sky: why it matters
We know that the night sky is full of life. Animals moving around up there can have big impacts on us at ground level. But we really don’t know that much about what actually goes on in the night sky. Most insects and even bats are too small to carry GPS and other telemetry tags that will give us detailed movement information. Remote-sensing tools like radar are useful but there is much that they cannot tell us. What insects are flying, at what altitudes? What environmental cues, like wind speed and temperature, are they using to find and remain at those altitudes? Are the bats finding them wherever they are? What bat species are flying that high, and are they foraging or migrating? What birds are migrating? Are there birds flying around up there outside of migration? As a Nat Geo Explorer, I’m looking forward to tackling these questions!
What we know so far
We’ve already begun to answer some of these questions with our current system, which involves a special helium balloon-kite that raises bat detectors up to different altitudes. Using this system we showed that bats change their behavior to forage more at higher altitudes when moths are migrating. We also recently used it to “ground-truth” specialized radar systems. Our current system has been limited by wind speed to about 250 meters in altitude. However, we know that animals are using the night sky even higher than that!
Thanks to National Geographic, the next generation of our aerostat system will fly as high as 500 meters (about 2,000 feet) in the night sky. In addition, we’ll expand the echolocation recording equipment to include an array of multiple microphones. This will enable us to use triangulation to track the movements of bats in three dimensional space. That will be tricky, because nobody has tried to do this with an array that is moving itself! So we’ll need to use sensors like accelerometers to track that movement, and then figure out how to incorporate those data into our analysis.
We plan to also incorporate night vision video capture with the array so that we can see what the bats are doing. If we’re super lucky, we might actually witness bats capturing insects way up there, for the first time! Last but not least, this new system will include audio recorders for bird calls in addition to bat calls. Migratory birds fly very high at night, and many of them call while flying. We actually don’t know how far those calls carry — some can be recorded on the ground but probably not all of them. Our system will allow us to figure out which species of birds are migrating and at what altitude. Our plan is to make as much of this system open source as possible so that others can also explore life in the night sky.
Clearly there will be many challenges and adventures ahead. But this Explorer is up for the adventure!