Wasn't this exactly what the Project Mogul, the project thought to have sparked off the entire Roswell alien saga, was doing? https://en.wikipedia.org/wiki/Pro

Wasn't this exactly what the Project Mogul, the project thought to have sparked off the entire Roswell alien saga, was doing? https://en.wikipedia.org/wiki/Project_Mogul https://en.wikipedia.org/wiki/Project_Mogul Is this the first time that the channel has been publicly verified? Or, in other words, has the data for the existence of this channel been known for some time and kept classified? Or, is there something else going on? edit - yes, I've read the article. And while the article mentions this. It doesn't seem to go into detail about what Mogul actually found, and how this diverges. At least not to my understanding of the text, > After geophysicist Maurice Ewing discovered the SOFAR channel in 1944, he set out to find an analogous layer in the sky. At an altitude of between 10 and 20 kilometers is the tropopause, the boundary between the troposphere, the lowest layer of the atmosphere (where weather occurs), and the stratosphere. Like the marine SOFAR, the tropopause represents a cold region, where sound waves should travel slower and farther. An acoustic waveguide in the atmosphere, Ewing reasoned, would allow the U.S. Air Force to listen for nuclear weapon tests detonated by the Soviet Union. He instigated a top-secret experiment, code-named Project Mogul, that sent up hot air balloons equipped with infrasound microphones. > The instruments often malfunctioned in the high winds, and in 1947, debris from one balloon crashed just outside of Roswell, New Mexico; that crash sparked one of the most famous UFO conspiracy theories in history. Soon after, the military disbanded the project. But the mission wasn’t declassified for nearly 50 years. By then, Cold War tensions had settled and research in atmospheric acoustics had all but died out, says Stephen McNutt, a volcanic seismologist at the University of South Florida. “All of a sudden, the rug got pulled out, and infrasound wasn’t funded for 30 or 40 years,” he says. > But Sarah Albert, a geophysicist at Sandia National Laboratories in New Mexico, never gave up on the idea. She was intrigued by the potential of new solar-powered balloons that can float passively at stable altitudes and wireless telemetry that can broadcast data continuously over long ranges. I raised this because the article seems to be a bit incorrect, because geophysical MASINT continues to be an important part of intelligence gathering. https://en.wikipedia.org/wiki/Geophysical_MASINT https://en.wikipedia.org/wiki/Geophysical_MASINT The DNI has a public primer on it, https://www.dni.gov/files/ODNI/documents/21-113_MASINT_Primer__2022.pdf https://www.dni.gov/files/ODNI/documents/21-113_MASINT_Prime... Directly after Project Mogul, there was Project Skyhook, https://en.wikipedia.org/wiki/Skyhook_balloon https://en.wikipedia.org/wiki/Skyhook_balloon , which IIRC included a number of sensors including microphones. I'm struggling to understand whether or not they actually verified something that seemingly was known since the 1940s?