The Soviet Union beat the US to this, with the October 4, 1957 orbiting of Sputnik 1, and later beat the US to the first human in space, Yuri Gagarin, on April 12, 1961. The race peaked with the July 20, 1969 US landing of the first humans on the Moon with Apollo 11.
The definition of a luminary is an object giving off light, or a personality that is well known or enlightening to mankind. An example of a luminary is a candle.
Illuminance is the amount of light striking a surface â also known as incident light, where the âincidentâ is the beam of light actually landing on the surface. Lumens are a measure of the quantity of light, referred to as luminous flux or just flux, emitted by a light source.