Atmosphere of Earth years ago. About 3.4 billion years ago, nitrogen formed the major part of the then stable "second atmosphere". The influence of life has to be taken into account rather soon in the history of the atmosphere, because hints of early life-forms appear as early as 3.5 billion years ago. How Earth at that time maintained a climate warm enough for liquid water and life, if the early Sun put out 30% lower solar radiance than today, is a puzzle known as the "faint young Sun paradox". The geological record however shows a continuous relatively warm surface during the complete early
NRIST S-80 series UAV NRIST S-80 series UAV NRIST S-80 series UAVs are Chinese UAVs developed by Nanjing Research Institute of Simulation Technology (南京模拟技术研究所) (NRIST), also known as the 60th Research Institute of People's Liberation Army General Staff Department (总参六十所), an ISO 9001 certified research/production facility headquartered in Nanjing. S-80 series UAVs are part of larger NRIST S-series UAVs. S-80 drone is a fixed wing UAV developed by NRIST, and it is a development of earlier NRIST B-9H drone. Like its predecessor B-9H, S-80 is also developed for naval use on board ships. S-80 drone is constructed of fiber glass reinforced plastic with aluminum