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  2. Mercury (planet) - Wikipedia

    en.wikipedia.org/wiki/Mercury_(planet)

    Mercury has an orbital speed of 47.4 km/s (29.5 mi/s), whereas Earth's orbital speed is 29.8 km/s (18.5 mi/s). [112] Therefore, the spacecraft must make a larger change in velocity ( delta-v ) to get to Mercury and then enter orbit, [ 187 ] as compared to the delta-v required for, say, Mars planetary missions .

  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. Escape velocity - Wikipedia

    en.wikipedia.org/wiki/Escape_velocity

    Escape speed at a distance d from the center of a spherically symmetric primary body (such as a star or a planet) with mass M is given by the formula [2] [3] = = where: G is the universal gravitational constant (G ≈ 6.67 × 10 −11 m 3 ⋅kg −1 ⋅s −2 ‍ [4])

  5. Astronomy on Mercury - Wikipedia

    en.wikipedia.org/wiki/Astronomy_on_Mercury

    Approximately four (Earth) days before perihelion, the angular speed of Mercury's orbit exactly matches its rotational velocity, so that the Sun's apparent motion stops. At perihelion, Mercury's orbital angular velocity slightly exceeds the rotational velocity, making the Sun appear to go retrograde.

  6. Earth's rotation - Wikipedia

    en.wikipedia.org/wiki/Earth's_rotation

    The tangential speed of Earth's rotation at a point on Earth can be approximated by multiplying the speed at the equator by the cosine of the latitude. [42] For example, the Kennedy Space Center is located at latitude 28.59° N, which yields a speed of: cos(28.59°) × 1,674.4 km/h = 1,470.2 km/h.

  7. Orders of magnitude (speed) - Wikipedia

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

    Speed of International Space Station and typical speed of other satellites such as the Space Shuttle in low Earth orbit. 7,777: 28,000: 17,400: 2.594 × 10 −5: Speed of propagation of the explosion in a detonating cord. 10 4: 10,600 38,160 23,713.65 0.00004 Speed of propagation of the explosion of Octanitrocubane (ONC). 11,107: 39,985.2: ...

  8. Orbital spaceflight - Wikipedia

    en.wikipedia.org/wiki/Orbital_spaceflight

    This figure is mainly (~7.8 km/s) for horizontal acceleration needed to reach orbital speed, but allows for atmospheric drag (approximately 300 m/s with the ballistic coefficient of a 20 m long dense fueled vehicle), gravity losses (depending on burn time and details of the trajectory and launch vehicle), and gaining altitude.

  9. Tests of general relativity - Wikipedia

    en.wikipedia.org/wiki/Tests_of_general_relativity

    Transit of Mercury on November 8, 2006 with sunspots #921, 922, and 923 The perihelion precession of Mercury. Under Newtonian physics, an object in an (isolated) two-body system, consisting of the object orbiting a spherical mass, would trace out an ellipse with the center of mass of the system at a focus of the ellipse.