Terrestrial gamma-ray flashes occur above some thunderstorms and propagate out into space. These high-energy discharges of photons were only discovered less than 25 years ago when a NASA spacecraft designed to observe cosmic gamma-ray bursts from outer space detected flashes that seemed to come from Earth itself.
Source:
https://phys.org/news/2019-05-first-ever-image-terrestrial-gamma-ray.html