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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; it is widely but not universally accepted.

  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. Sub-orbital spaceflight - Wikipedia

    en.wikipedia.org/wiki/Sub-orbital_spaceflight

    In this case the lowest required delta-v, to reach 100 km altitude, is about 1.4 km/s. Moving slower, with less free-fall, would require more delta-v. [citation needed] Compare this with orbital spaceflights: a low Earth orbit (LEO), with an altitude of about 300 km, needs a speed around 7.7 km/s, requiring a delta-v of about 9.2 km/s.

  5. Low Earth orbit - Wikipedia

    en.wikipedia.org/wiki/Low_Earth_orbit

    The International Space Station is in LEO about 400 to 420 kilometres (250 to 260 mi) above the Earth's surface. [14] The station’s orbit decays by about 2 km/month (1.2 mi/month) and consequently needs re-boosting a few times a year. The Iridium telecom satellites orbit at about 780 km (480 mi).

  6. Solar irradiance - Wikipedia

    en.wikipedia.org/wiki/Solar_irradiance

    The solar flux density (insolation) onto a plane tangent to the sphere of the Earth, but above the bulk of the atmosphere (elevation 100 km or greater) is: = {⁡ ⁡ > ⁡ () The average of Q over a day is the average of Q over one rotation, or the hour angle progressing from h = π to h = −π : Q ¯ day = − 1 2 π ∫ π − π Q d h ...

  7. Earth radius - Wikipedia

    en.wikipedia.org/wiki/Earth_radius

    Earth radius (denoted as R 🜨 or R E) is the distance from the center of Earth to a point on or near its surface. Approximating the figure of Earth by an Earth spheroid (an oblate ellipsoid), the radius ranges from a maximum (equatorial radius, denoted a) of nearly 6,378 km (3,963 mi) to a minimum (polar radius, denoted b) of nearly 6,357 km (3,950 mi).

  8. 99% of humans are about to experience sunlight at the same time

    www.aol.com/weather/99-humans-experience...

    At 7:15 a.m. EDT on Saturday, July 8, around 99% of the Earth's population will see sunlight in the sky - as long as it isn't cloudy. ... (AP Photo/Michael Probst) It's time to break out the ...

  9. Thermosphere - Wikipedia

    en.wikipedia.org/wiki/Thermosphere

    The total mass of the atmosphere is M = ρ A H ≃ 1 kg/cm 2 within a column of one square centimeter above the ground (with ρ A = 1.29 kg/m 3 the atmospheric density on the ground at z = 0 m altitude, and H ≃ 8 km the average atmospheric scale height). Eighty percent of that mass is concentrated within the troposphere. The mass of the ...