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  2. Atmospheric escape - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_escape

    The projectile can impart momentum, and thereby facilitate escape of the atmosphere, in three main ways: (a) the meteoroid heats and accelerates the gas it encounters as it travels through the atmosphere, (b) solid ejecta from the impact crater heat atmospheric particles through drag as they are ejected, and (c) the impact creates vapor which ...

  3. Escape velocity - Wikipedia

    en.wikipedia.org/wiki/Escape_velocity

    In most situations it is impractical to achieve escape velocity almost instantly, because of the acceleration implied, and also because if there is an atmosphere, the hypersonic speeds involved (on Earth a speed of 11.2 km/s, or 40,320 km/h) would cause most objects to burn up due to aerodynamic heating or be torn apart by atmospheric drag. For ...

  4. Atmospheric entry - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_entry

    The Stardust sample-return capsule was the fastest man-made object ever to reenter Earth's atmosphere, at 28,000 mph (ca. 12.5 km/s) at 135 km altitude. This was faster than the Apollo mission capsules and 70% faster than the Shuttle. [1] PICA was critical for the viability of the Stardust mission, which returned to Earth in 2006.

  5. Terminal velocity - Wikipedia

    en.wikipedia.org/wiki/Terminal_velocity

    Based on air resistance, for example, the terminal speed of a skydiver in a belly-to-earth (i.e., face down) free fall position is about 55 m/s (180 ft/s). [3] This speed is the asymptotic limiting value of the speed, and the forces acting on the body balance each other more and more closely as the terminal speed is approached. In this example ...

  6. Atmosphere of Earth - Wikipedia

    en.wikipedia.org/wiki/Atmosphere_of_Earth

    The troposphere is the lowest layer of Earth's atmosphere. It extends from Earth's surface to an average height of about 12 km (7.5 mi; 39,000 ft), although this altitude varies from about 9 km (5.6 mi; 30,000 ft) at the geographic poles to 17 km (11 mi; 56,000 ft) at the Equator, [17] with some variation due

  7. Atmospheric physics - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_physics

    Within the atmospheric sciences, atmospheric physics is the application of physics to the study of the atmosphere.Atmospheric physicists attempt to model Earth's atmosphere and the atmospheres of the other planets using fluid flow equations, radiation budget, and energy transfer processes in the atmosphere (as well as how these tie into boundary systems such as the oceans).

  8. Atmospheric circulation - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_circulation

    The Hadley cell is a closed circulation loop which begins at the equator. There, moist air is warmed by the Earth's surface, decreases in density and rises. A similar air mass rising on the other side of the equator forces those rising air masses to move poleward. The rising air creates a low pressure zone near the equator.

  9. Speed of light - Wikipedia

    en.wikipedia.org/wiki/Speed_of_Light

    from geostationary orbit to Earth: 119 ms: the length of Earth's equator: 134 ms: from Moon to Earth: 1.3 s: from Sun to Earth (1 AU) 8.3 min: one light-year: 1.0 year: one parsec: 3.26 years: from the nearest star to Sun (1.3 pc) 4.2 years: from the nearest galaxy to Earth: 70 000 years: across the Milky Way: 87 400 years: from the Andromeda ...