Ever heard of the Ignorosphere? It’s what scientists have jokingly nicknamed the mesosphere, the third atmospheric layer from Earth’s surface. It’s always been tough for researchers to access and so has been largely ignored. But that’s about to change, thanks to work done by Project PoSSUM (Polar Suborbital Science in the Upper Mesosphere).
While unmanned rockets, satellites and balloons — most notably NASA’s AIM satellite — have taken images of and collected data from the layer in the past, new suborbital vehicles will make it possible to send actual human scientists to the mesosphere to study noctilucent (NLC) clouds. These ragged, spidery clouds began appearing in the late 1800s, and their increasing frequency and geographic spread are believed to be a marker for climate change. They’ve been difficult to study, however: They’re too high for detailed data collection via ground-based instruments, balloons or aircraft, and too low for orbital satellites. The complex equipment that can measure fine-scale changes in the clouds’ composition needs a human operator.
Project PoSSUM’s executive director, Jason Reimuller, says suborbital rocket planes are scheduled to launch from Alaska in 2018. They’ll head into the Ignorosphere to study the composition of the atmosphere in various ways.
In addition to shooting traditional video of the NLC clouds, an automated infrared imager will record a layer of molecules — the airglow — that sits just above them. The images will give experts a better idea of the mesosphere's overall structure.
As the vehicle passes through clouds, a shoebox-sized instrument will capture air to compare carbon dioxide and nitric oxide levels with surface levels.
An aerosol sampler will collect fine particles from the atmosphere, believed to be leftover meteor bits, which may explain how the clouds form in the first place.
The Mesosphere Clear Air Turbulence instrument will use pressure data to calculate temper-atures that will help determine how the clouds grow.
[This article originally appeared in print as "Destination: Ignorosphere."]