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  2. Earth's orbit - Wikipedia

    en.wikipedia.org/wiki/Earth's_orbit

    One complete orbit takes 365.256 days (1 sidereal year), during which time Earth has traveled 940 million km (584 million mi). [2] 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 ...

  3. Orbital period - Wikipedia

    en.wikipedia.org/wiki/Orbital_period

    The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy , it usually applies to planets or asteroids orbiting the Sun , moons orbiting planets, exoplanets orbiting other stars , or binary stars .

  4. Kepler's laws of planetary motion - Wikipedia

    en.wikipedia.org/wiki/Kepler's_laws_of_planetary...

    The red ray rotates at a constant angular velocity and with the same orbital time period as the planet, =. S: Sun at the primary focus, C: Centre of ellipse, S': The secondary focus. In each case, the area of all sectors depicted is identical.

  5. List of time periods - Wikipedia

    en.wikipedia.org/wiki/List_of_time_periods

    Early modern period – The chronological limits of this period are open to debate. It emerges from the Late Middle Ages (c. 1500), demarcated by historians as beginning with the fall of Constantinople in 1453, in forms such as the Italian Renaissance in the West, the Ming dynasty in the East, and the rise of the Aztecs in the New World.

  6. Sidereal time - Wikipedia

    en.wikipedia.org/wiki/Sidereal_time

    The March equinox itself precesses slowly westward relative to the fixed stars, completing one revolution in about 25,800 years, so the misnamed "sidereal" day ("sidereal" is derived from the Latin sidus meaning "star") is 0.0084 seconds shorter than the stellar day, Earth's actual period of rotation relative to the fixed stars. [3]

  7. Axial precession - Wikipedia

    en.wikipedia.org/wiki/Axial_precession

    The stars viewed from Earth are seen to proceed from east to west daily (at about 15 degrees per hour), due to the Earth's diurnal motion, and yearly (at about 1 degree per day), due to the Earth's revolution around the Sun. At the same time the stars can be observed to anticipate slightly such motion, at the rate of approximately 50 arc ...

  8. The time when a day on Earth was just 19 hours long - AOL

    www.aol.com/lifestyle/day-earth-used-just-19...

    Known affectionately to scientists as the "boring billion," there was a seemingly endless period in the world's history when the length of a day stayed put. The time when a day on Earth was just ...

  9. History of Earth - Wikipedia

    en.wikipedia.org/wiki/History_of_Earth

    In geochronology, time is generally measured in mya (million years ago), each unit representing the period of approximately 1,000,000 years in the past. The history of Earth is divided into four great eons, starting 4,540 mya with the formation of the planet.