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  2. Earth's orbit - Wikipedia

    en.wikipedia.org/wiki/Earth's_orbit

    The point towards which the Earth in its solar orbit is directed at any given instant is known as the "apex of the Earth's way". [4] [5] From a vantage point above the north pole of either the Sun or Earth, Earth would appear to revolve in a counterclockwise direction around the Sun. From the same vantage point, both the Earth and the Sun would ...

  3. Orbital speed - Wikipedia

    en.wikipedia.org/wiki/Orbital_speed

    In gravitationally bound systems, the orbital speed of an astronomical body or object (e.g. planet, moon, artificial satellite, spacecraft, or star) is the speed at which it orbits around either the barycenter (the combined center of mass) or, if one body is much more massive than the other bodies of the system combined, its speed relative to the center of mass of the most massive body.

  4. Galactic year - Wikipedia

    en.wikipedia.org/wiki/Galactic_year

    The Solar System is traveling at an average speed of 230 km/s (828,000 km/h) or 143 mi/s (514,000 mph) within its trajectory around the Galactic Center, [3] a speed at which an object could circumnavigate the Earth's equator in 2 minutes and 54 seconds; that speed corresponds to approximately 1/1300 of the speed of light.

  5. Earth's rotation - Wikipedia

    en.wikipedia.org/wiki/Earth's_rotation

    Earth's movement along its nearly circular orbit while it is rotating once around its axis requires that Earth rotate slightly more than once relative to the fixed stars before the mean Sun can pass overhead again, even though it rotates only once (360°) relative to the mean Sun. [n 5] Multiplying the value in rad/s by Earth's equatorial ...

  6. Sun-synchronous orbit - Wikipedia

    en.wikipedia.org/wiki/Sun-synchronous_orbit

    An orbit will be Sun-synchronous when the precession rate ρ = ⁠ dΩ / dt ⁠ equals the mean motion of the Earth about the Sun n E, which is 360° per sidereal year (1.990 968 71 × 10 −7 rad/s), so we must set n E = ⁠ ΔΩ E / T E ⁠ = ρ = ⁠ ΔΩ / T ⁠, where T E is the Earth orbital period, while T is the period of the spacecraft ...

  7. Ecliptic - Wikipedia

    en.wikipedia.org/wiki/Ecliptic

    Again, this is a simplification, based on a hypothetical Earth that orbits at uniform speed around the Sun. The actual speed with which Earth orbits the Sun varies slightly during the year, so the speed with which the Sun seems to move along the ecliptic also varies. For example, the Sun is north of the celestial equator for about 185 days of ...

  8. Orders of magnitude (speed) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(speed)

    Fastest projectile velocity (1994). [24] 16,210: 58,356: 36,261 0.00005: Escape speed from Earth by NASA New Horizons spacecraft—Fastest escape velocity. 17,000: 61,000: 38,000 0.00006: The approximate speed of the Voyager 1 probe relative to the Sun, when it exited the Solar System. [25] 29,800: 107,280: 66,700 0.00010: Speed of the Earth in ...

  9. Specific orbital energy - Wikipedia

    en.wikipedia.org/wiki/Specific_orbital_energy

    It is related to the hyperbolic excess velocity (the orbital velocity at infinity) by = =. It is relevant for interplanetary missions. Thus, if orbital position vector ( r {\displaystyle \mathbf {r} } ) and orbital velocity vector ( v {\displaystyle \mathbf {v} } ) are known at one position, and μ {\displaystyle \mu } is known, then the energy ...