Future of Earth the ozone layer that protects the surface from ultraviolet (UV) radiation from the Sun. An increase in UV-B radiation of only 10–30% is sufficient to cause a significant impact to life; particularly to the phytoplankton that form the base of the oceanic food chain. A supernova explosion at a distance of 26 light years will reduce the ozone column density by half. On average, a supernova explosion occurs within 32 light years once every few hundred million years, resulting in a depletion of the ozone layer lasting several centuries. Over the next two billion years, there will be about 20
Zombies of the Stratosphere and viewers found the serial to be relatively dull and unimaginative, not as interesting as "Radar Men from the Moon". The use of stock footage from earlier serials is not quite as overwhelming as seen in the earlier or later Cody outings, as greater emphasis is placed on fistfights rather than scenes using the rocket back-pack. Holdren's performance is often stiff and amateurish, especially when compared to the professionalism of the old Republic pros who surround him on screen. Cline describes this serial as just a "quickie." Zombies of the Stratosphere Zombies of the Stratosphere is a 1952 black-and-white Republic