Mysterious sounds in stratosphere can't be traced to any known source
Solar-powered balloons floating 20 kilometres above ground have recorded inaudible low-frequency signals that have so far not been traced ba..
https://www.newscientist.com/article/2373236-mysterious-sounds-in-stratosphere-cant-be-traced-to-any-known-source/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home
https://www.newscientist.com/article/2373236-mysterious-sounds-in-stratosphere-cant-be-traced-to-any-known-source/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home
