Why do things burn up on re-entry into earth's atmosphere?

1. 59

   Jangaplanetposted 12 years ago

   Why do things burn up on re-entry into earth's atmosphere?

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2. 59

   HarshitGposted 12 years ago

   The main reason why things heat up when they hit the Earth’s atmosphere is they've got huge amounts of kinetic energy - they're going incredibly fast.  When they bash into the Earth’s atmosphere, most of the heating is actually because the air they bash into hasn’t got time to get out of the way, so the air get compressed, and when you compress air - you may have noticed if you've ever pumped off a bicycle tire very, very quickly - it gets hotter.  So the air in front of the asteroid heats up very, very incredibly hot, and that starts to erode the surface of the meteorite and you get this tail of a very, very hot stuff behind the meteorite which you see as a shooting star.
   
   With very, very small things, because the friction is so much larger compared to their mass, they tend to lose their speed very high up in the atmosphere much more gently, so they slow down much more gently and don’t get as hot.  Once they slow down enough, they just drift down like dust does gently through the atmosphere.  So, it is conceivable that something like a bacteria on a small dust grain could survive, whereas a big lump would melt up very quickly.

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3. 62

   Evan G Rogersposted 12 years ago

   Heat = atoms smashing into one another.
   
   Hot is when the atoms are smashing into each other a lot at high speed.
   
   There are no atoms in outer space, so meteors, etc,?Are freezing.
   
   The second the meteor enters our atmosphere, it hits air.
   
   Thus, we have very fast meteors hitting atoms.
   
   Thus, we have heat.

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4. 60

   ackman1465posted 12 years ago

   If you remember that "air" really is "something" (it's a gas).... then consider that, when a meteor or a space vehicle or a piece of space debris starts to move toward Earth.... and, at the speeds that they travel (a space shuttle begins its descent at about 18,000 MPH!).... then the FRICTION of the air upon the impacting surface becomes so great that a lot of heat is developed.   
   
   When one of the space shuttles broke apart (over Texas and Louisiana) we learned that there were tiles on the "under-side" that impinged on the Earth's environment (it lead, going in to the air/atmosphere) the temperatures were great enough to melt the metal that was under the tiles.   With the tiles compromised, the high temp impinged upon the underside of the shuttle's metal belly and started making holes in it.....   until those holes upset the aerodynamics of the vehicle, caused it to go out of control and, ultimately, break apart and fall to Earth....
   
   Most space debris ("meteors" or "shooting stars") are small objects (few are even as large as a baseball), which glow hot upon starting in to the Earth's air atmosphere.... and they quickly break apart and the resulting debris (rather dustlike) falls harmlessly to Earth....  As many as several TONS of space debris intersects with Earth each year!!!!
   
   Very large objects, like those that struck Crater Lake, Arizona or the Russian steppe, in the early 1900s can very very destructive when they land....

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5. 92

   Faceless39posted 12 years ago

   In the case of space ships, they're solid and moving super fast.  Think of running really fast and doing a belly dive into some carpet.  Friction burns are no fun, and it's a similar idea to what happens when a space ship "hits" the atomic gases of the atmosphere on re-entry.

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