The planet Neptune, for example, takes almost 165 years to orbit the sun. According to Keplers laws, Mercury must have the shortest orbital period (88 Earth-days); thus, it has the highest orbital speed, averaging 48 kilometers per second. Orbital Data Have all your study materials in one place. Let us know if you have suggestions to improve this article (requires login). Numerous scientific discoveries cast doubt on this classification, and after the discovery of, When discovered, Charon, the moon of Pluto, was found to be very large, leading to the declaration by many that the, When discovered, these bodies were briefly hailed as the tenth and eleventh planets by the press, but it was then decided that 15760 Albion was the prototype of, The discovery of Eris, hailed worldwide by the press as the tenth planet, prompted the, This page was last edited on 22 April 2023, at 22:28. Orbital period is inversely proportional to orbital speed. Fig 1 - Triangle formed by position vectors and \(\triangle{\vec{r}}\) in a circular orbit. The mass of the celestial body we orbit around is important for orbital period calculations. ", "Planetary Motion: The History of an Idea That Launched the Scientific Revolution", "The Copernican Model: A Sun-Centered Solar System", "The Discovery of the Galilean Satellites", "Montaigne, Peiresc, Gassendi, and Cassini - The Provenal Humanists and Copernicus", "An Extract of the Journal Des Scavans. The further away a planet is from the sun, the longer its orbital period. List of former planets $$\begin{align*}v&=\sqrt{\frac{GM}r},\\v&=\sqrt{\frac{\left(6.67\times10^{-11}\;\frac{\mathrm m^3}{\mathrm s^2\mathrm{kg}}\right)\left(1.99\times10^{27}\;\mathrm{kg}\right)}{\left(5.2\;\mathrm{AU}\right)\left(1.49\times10^{11}\;{\displaystyle\frac{\mathrm m}{\mathrm{AU}}}\right)},}\\v&=13\;\frac{\mathrm{km}}{\mathrm s}.\end{align*}$$. We know eight planets, beginning with Mercury closest to the Sun and extending outward to Neptune. WebOther articles where orbital period is discussed: Neptune: Basic astronomical data: Having an orbital period of 164.79 years, Neptune has circled the Sun only once since its discovery in September 1846. Sometimes Neptune is even farther from the Sun than dwarf planet Pluto. Its mass is 16.1 Jupiters, it takes 51 years to complete one orbit of its star, and is 16.9 AU from its star.
