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
S band companies are allowed two years to start providing pan-European MSS services for 18 years. Allocated frequencies are 1.98 to 2.01 GHz for Earth to space communications, and from 2.17 to 2.2 GHz for space to Earth communications. Eutelsat W2A satellite launched in April, 2009 and located at 10° East is currently the unique satellite in Europe operating on S band frequencies. In some countries, S band is used for Direct-to-Home satellite television (unlike similar services in most countries, which use K band). The frequency typically allocated for this service is 2.5 to 2.7 GHz (LOF 1.570 GHz). IndoStar-1 was the