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  2. Kármán line - Wikipedia

    en.wikipedia.org/wiki/Kármán_line

    Earth's atmosphere photographed from the International Space Station.The orange and green line of airglow is at roughly the altitude of the Kármán line. [1]The Kármán line (or von Kármán line / v ɒ n ˈ k ɑːr m ɑː n /) [2] is a conventional definition of the edge of space.

  3. Scale height - Wikipedia

    en.wikipedia.org/wiki/Scale_height

    The earth atmosphere's ... with the equation for H given above to ... level value of ρ 0 roughly equal to 1.2 kg⋅m −3. At an altitude over 100 km, the atmosphere ...

  4. Outer space - Wikipedia

    en.wikipedia.org/wiki/Outer_space

    The altitude of 118 km (73.3 mi) above Earth was the midpoint for charged particles transitioning from the gentle winds of the Earth's atmosphere to the more extreme flows of outer space. The latter can reach velocities well over 268 m/s (880 ft/s).

  5. List of orbits - Wikipedia

    en.wikipedia.org/wiki/List_of_orbits

    In practice, only 1:1 ratio (geosynchronous) and 1:2 ratios (semi-synchronous) are common. Geosynchronous orbit (GSO): An orbit around the Earth with a period equal to one sidereal day, which is Earth's average rotational period of 23 hours, 56 minutes, 4.091 seconds. For a nearly circular orbit, this implies an altitude of approximately 35,786 ...

  6. Orders of magnitude (length) - Wikipedia

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

    The nanometre (SI symbol: nm) is a unit of length in the metric system equal to 10 −9 metres (⁠ 1 / 1 000 000 000 ⁠ m = 0. 000 000 001 m). To help compare different orders of magnitude , this section lists lengths between 10 −9 and 10 −8 m (1 nm and 10 nm).

  7. Sub-orbital spaceflight - Wikipedia

    en.wikipedia.org/wiki/Sub-orbital_spaceflight

    An intercontinental ballistic missile is defined as a missile that can hit a target at least 5500 km away, and according to the above formula this requires an initial speed of 6.1 km/s. Increasing the speed to 7.9 km/s to attain any point on Earth requires a considerably larger missile because the amount of fuel needed goes up exponentially ...

  8. Isostasy - Wikipedia

    en.wikipedia.org/wiki/Isostasy

    Isostasy (Greek ísos 'equal', stásis 'standstill') or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its thickness and density. This concept is invoked to explain how different topographic heights can exist at Earth ...

  9. Geopotential height - Wikipedia

    en.wikipedia.org/wiki/Geopotential_height

    Geopotential height or geopotential altitude is a vertical coordinate referenced to Earth's mean sea level (assumed zero geopotential) that represents the work involved in lifting one unit of mass over one unit of length through a hypothetical space in which the acceleration of gravity is assumed constant. [1]