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Orbit of the Solar System: 17,200 pc 5.31×10 17: The average diameter of the orbit of the Solar System relative to the Galactic Center. The Sun's orbital radius is roughly 8,600 parsecs, or slightly over halfway to the galactic edge. One orbital period of the Solar System lasts between 225 and 250 million years. [34] [35] Milky Way Galaxy ...
Ignoring the influence of other Solar System bodies, Earth's orbit, also called Earth's revolution, is an ellipse with the Earth–Sun barycenter as one focus with a current eccentricity of 0.0167. Since this value is close to zero, the center of the orbit is relatively close to the center of the Sun (relative to the size of the orbit).
Diagram of the early Solar System's protoplanetary disk, out of which Earth and other Solar System bodies formed. The Solar System formed at least 4.568 billion years ago from the gravitational collapse of a region within a large molecular cloud. [b] This initial cloud was likely several light-years across and probably birthed several stars. [14]
NOAA Solar Calculator, at the NOAA Earth System Research Laboratories's Global Monitoring Division website. NOAA's declination and sun position calculator; HORIZONS System, at the JPL website. Very accurate positions of Solar System objects based on the JPL DE series ephemerides. General ephemerides of the solar system bodies, at the IMCCE ...
The average of the true solar day during the course of an entire year is the mean solar day, which contains 86,400 mean solar seconds. Currently, each of these seconds is slightly longer than an SI second because Earth's mean solar day is now slightly longer than it was during the 19th century due to tidal friction. The average length of the ...
Solar longitude, commonly abbreviated as Ls, is the ecliptic longitude of the Sun, i.e. the position of the Sun on the celestial sphere along the ecliptic.It is also an effective measure of the position of the Earth (or any other Sun-orbiting body) in its orbit around the Sun, [1] usually taken as zero at the moment of the vernal equinox. [2]
Earth orbits the Sun, making Earth the third-closest planet to the Sun and part of the inner Solar System. Earth's average orbital distance is about 150 million km (93 million mi), which is the basis for the astronomical unit (AU) and is equal to roughly 8.3 light minutes or 380 times Earth's distance to the Moon .
Ecliptic coordinates are convenient for specifying positions of Solar System objects, as most of the planets' orbits have small inclinations to the ecliptic, and therefore always appear relatively close to it on the sky. Because Earth's orbit, and hence the ecliptic, moves very little, it is a relatively fixed reference with respect to the stars.