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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. Thermosphere - Wikipedia

    en.wikipedia.org/wiki/Thermosphere

    The density of the Earth's atmosphere decreases nearly exponentially with altitude. 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).

  4. Upper-atmospheric lightning - Wikipedia

    en.wikipedia.org/wiki/Upper-atmospheric_lightning

    The red ring marks where the pulse hit the Earth's ionosphere. The duration of the "lightning" is about one millisecond, the "donut" has a diameter measured from the photo of approximately 360 km and a height above the ground of about 90/100 km. The distance for this type of photo must be between 100 and 600 km.

  5. Quizlet - Wikipedia

    en.wikipedia.org/wiki/Quizlet

    [6] [7] [8] Quizlet's blog, written mostly by Andrew in the earlier days of the company, claims it had reached 50,000 registered users in 252 days online. [9] In the following two years, Quizlet reached its 1,000,000th registered user. [10] Until 2011, Quizlet shared staff and financial resources with the Collectors Weekly website. [11]

  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. Atmospheric electricity - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_electricity

    Atmospheric electricity is always present, and during fine weather away from thunderstorms, the air above the surface of Earth is positively charged, while the Earth's surface charge is negative. This can be understood in terms of a difference of potential between a point of the Earth's surface, and a point somewhere in the air above it.

  8. Orders of magnitude (length) - Wikipedia

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

    Depth of the Challenger Deep in the Mariana Trench, the deepest-known point on Earth's surface 27 km Circumference of the Large Hadron Collider, as of May 2010 the largest and highest energy particle accelerator: 42.195 km Length of a marathon: 10 5: 100 km: 100 km The distance the IAU considers to be the limit to space, called the Karman line

  9. Atmosphere of Earth - Wikipedia

    en.wikipedia.org/wiki/Atmosphere_of_Earth

    The stratosphere is the second-lowest layer of Earth's atmosphere. It lies above the troposphere and is separated from it by the tropopause. This layer extends from the top of the troposphere at roughly 12 km (7.5 mi; 39,000 ft) above Earth's surface to the stratopause at an altitude of about 50 to 55 km (31 to 34 mi; 164,000 to 180,000 ft).