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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.
Transatmospheric orbit (TAO): geocentric orbits with an apogee above 100 km and perigee that intersects with the defined atmosphere. [4] Very low Earth orbit (VLEO) is defined as altitudes between approximately 100 - 450 km above Earth’s surface. [5] [6] Low Earth orbit (LEO): geocentric orbits with altitudes below 2,000 km (1,200 mi). [7]
These figures should be compared with the temperature and density of Earth's atmosphere plotted at NRLMSISE-00, which shows the air density dropping from 1200 g/m 3 at sea level to 0.125 g/m 3 at 70 km, a factor of 9600, indicating an average scale height of 70 / ln(9600) = 7.64 km, consistent with the indicated average air temperature over ...
5.0 Gm – closest approach of Comet Halley to Earth, happened on 10 April 837; 5.0 Gm – (proposed) Size of the arms of the giant triangle shaped Michelson interferometer of the Laser Interferometer Space Antenna (LISA) planned to start observations sometime in the 2030s. 7.9 Gm – diameter of Gamma Orionis, a blue dwarf or blue giant
The proportions assume that the total mass of the asteroid belt is 2.39 × 10 21 kg, or (12.4 ± 1.0) × 10 −10 M ☉. [ 12 ] Outside the top four, the ranking of all the asteroids is uncertain, as there is a great deal of overlap among the estimates.
A wide variety of sources [5] [6] [7] define LEO in terms of altitude.The altitude of an object in an elliptic orbit can vary significantly along the orbit. Even for circular orbits, the altitude above ground can vary by as much as 30 km (19 mi) (especially for polar orbits) due to the oblateness of Earth's spheroid figure and local topography.
Astronaut Bill Anders, who orbited the moon aboard Apollo 8 in 1968, has died in a plane crash off the coast of Washington state. His photo 'Earthrise' captivated the world.
The first term in (3) on the right is the global mean of the exospheric temperature (of the order of 1000 K). The second term [with P 2 0 = 0.5(3 sin 2 (φ)−1)] represents the heat surplus at lower latitudes and a corresponding heat deficit at higher latitudes (Fig. 2a). A thermal wind system develops with the wind toward the poles in the ...