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The mesosphere (/ ˈ m ɛ s ə s f ɪər, ˈ m ɛ z-, ˈ m iː s ə-,-z ə-/; [1] from Ancient Greek μέσος (mésos) 'middle' and -sphere) is the third layer of the atmosphere, directly above the stratosphere and directly below the thermosphere. In the mesosphere, temperature decreases as altitude increases.
Jilin bolide. The 2nd largest meteorite fall of the 20th century (after the Sikhote-Alin event). A fireball larger than the full moon was seen. There were several explosions then a violent breakup. [44] It yielded a piece at 1770 kg, more than twice the Chelyabinsk meteorite (654 kg), and total fragments collected was about 4 tons. [45] 1984 ...
Few meteorites are large enough to create large impact craters. Instead, they typically arrive at the surface at their terminal velocity and, at most, create a small pit. NWA 859 iron meteorite showing effects of atmospheric ablation The impact pit made by a 61.9-gram Novato meteorite when it hit the roof of a house on 17 October 2012.
Afterglow of the troposphere (orange), the stratosphere (blue) and the mesosphere (dark) at which atmospheric entry begins, leaving smoke trails, such as in this case of a spacecraft reentry. The mesosphere is the third highest layer of Earth's atmosphere, occupying the region above the stratosphere and below the thermosphere.
The stony objects, like chondritic meteorites, tend to burn, break up, or explode before leaving the upper atmosphere. Those that do make it to the surface need a minimum energy of about 10 Mt (4 × 10 16 J ) or about 50 m (160 ft) diameter to breach the lower atmosphere (this is for a stony object hitting at 20 kilometres per second (40,000 mph)).
Meteorites might look like boring bits of rock – but each one has a fascinating story. Curious Kids: what are meteorites made of and where do they come from? Skip to main content
A meteorite is a portion of a meteoroid or asteroid that survives its passage through the atmosphere and hits the ground without being destroyed. [22] Meteorites are sometimes, but not always, found in association with hypervelocity impact craters; during energetic collisions, the entire impactor may be vaporized, leaving no meteorites.
Some fragments may impact Earth as meteorites, if the meteor starts to break up or explodes in mid-air. These phenomena are then called Earth-grazing meteor processions and bolides . [ 1 ] Famous examples of Earth-grazers are the 1972 Great Daylight Fireball and the Meteor Procession of July 20, 1860 .