Classical planet Classical planet In classical antiquity, the seven classical planets were the seven non-fixed astronomical objects in the sky visible to the naked eye: Mars, Jupiter, Venus, Saturn, Mercury, the Sun, and the Moon. The word "planet" comes from two related Greek words, πλάνης "planēs" (whence πλάνητες ἀστέρες "planētes asteres" "wandering stars, planets") and πλανήτης "planētēs", both with the original meaning of "wanderer", expressing the fact that these objects move across the celestial sphere relative to the fixed stars. The term "planet" in modern terminology is only applied to natural satellites directly orbiting the Sun, so that of the seven classical
Nearest neighbour distribution Nearest neighbour distribution In probability and statistics, a nearest neighbor function, nearest neighbor distance distribution, nearest-neighbor distribution function or nearest neighbor distribution is a mathematical function that is defined in relation to mathematical objects known as point processes, which are often used as mathematical models of physical phenomena representable as randomly positioned points in time, space or both. More specifically, nearest neighbor functions are defined with respect to some point in the point process as being the probability distribution of the distance from this point to its nearest neighboring point in the same point process, hence they are used to