However, most pilots require 60â70 hours of flight time to complete training. The minimum age for a private pilot certificate is 16 for balloons and gliders, and 17 for powered flight (airplanes, helicopters, and gyroplanes). Pilots can begin training at any age and can solo balloons and gliders at age 14, powered aircraft at age 16.
A corona (Latin, ' crown ') is an aura of plasma that surrounds the sun and other celestial bodies. The Sun's corona extends millions of kilometres into space and is most easily seen during a total solar eclipse, but it is also observable with a coronagraph.The word corona is a Latin word meaning crown, from the Ancient Greek ÎºÎ¿ÏÏÎ½Î· (korÅnÄ, âgarland, wreathâ).The high temperature of the Sun's corona gives it unusual spectral features, which led some in the 19th century to suggest that it contained a previously unknown element,  coronium .he Coulomb logarithm is roughly 20 in the corona, with a mean temperature of 1 MK and a density of 10 15 particles/m 3, and about 10 in the chromosphere, where the temperature is approximately 10kK and the particle density is of the order of 10 18 particles/m 3, and in practice it can be assumed constant.
oroide definition: an alloy, mainly of copper, tin, and zinc, resembling gold, used in cheap jewelryOrigin of oroidefrom French orÃ©ide: see or and -ide... Definitions