why do objects burn when they enter the earth's atmosphere?

Question

mainly referring to meteors that disintegrate or burn off coming from outer space entering the earth's atmosphere.

Answer 1

'Cause of friction.

Answer 2

The objects enter the earths atmosphere at a very high speed. This causes a tremendous amount of friction with the air molecules in the upper atmosphere. This friction is what causes the items to burn up. The same thing happens to the space shuttle when it returns from space.

Answer 3

As many people have answered so far, objects "burn" in the atmosphere due to atmospheric drag against the object reentering at great speeds. A more correct definition of this process would be atmospheric heating. And to my knowledge there are no exact words defining this process, other than reentry. In order to remain in orbit, either around the Sun or around the Earth, objects need to travel at very high speeds. For instance, getting to low Earth orbit (and staying there) requires a speed of roughly 17,500 miles per hour. This is why massive rockets are required to get into orbit. Well, as the objects encounter the upper levels of the Earth's atmosphere they will start to lose some of this speed. As the objects get further into the atmosphere they begin encountering even more air molecules, providing further resistance against their forward motion slowing them down (and thus moving them closer to the Earth) even further. This process continues until the object cannot continue to radiatively cool itself, and is likely on a course to impact the Earth. Traveling at around 17,500 mph through the atmosphere is something like rubbing your arm very quickly on the carpet- it's going to get hot. Now depending upon the shape, velocity, mass and material of the object it can get incredibly hot, and even explode, before it impacts the Earth. Some materials are called "ablative" in that they melt at these high temperatures, keeping the "parent" object cool. Other materials and objects retain all of these heat. It's all part of the transfer of kinetic and potential energy, and involves some heavy physics that I won't get into. :) So hopefully this answers your question!

Answer 4

campbelp2002 is the first one who actually has the correct answer. Objects do not burn per se, they just heat up and disintegrate into hot gas; probably not very much is actually oxidized in a burning process. The heat is NOT caused by friction at all, this is a very common misconception. Instead, it is mostly caused by the object compressing the air in front of it, which increases in temperature as it becomes denser and heats up the object along with it. Spacecraft designed to reenter the Earth's atmosphere, such as space shuttles, are built with special surfaces so that they can resist the heat of reentering the atmosphere.

Answer 5

Friction...objects entering our atmosphere are coming in at a velocity of tens of thousands of miles per hour....maybe 20 miles a second. Contacting our atmosphere from space at that speed would be like hitting a brick wall...their integrity cannot hold up once it comes into friction with all those molecules.

Answer 6

There is a great amount of friction when you go from no gravity to our gravity. This friction is very intense and thus causes heat. (Like rubbing your hands together fast) The heat then disintegrates anything trying to enter our atmosphere. Pretty good design don't you think?

Answer 7

As you know air has mass and density, because its made of tiny particles called atoms. If you push on it it pushes back. When objects leave space and enter our atmosphere they travel at enormous speeds (exceeding 10 miles/second). They travel thought matter. In an effect similar to you rubbing your hands together the craft or object heats up from the friction.

Friction is the force that counteracts movement. Whenever matter is rubbed they bump and that kinetic energy is transformed into heat energy.

If you need furthered details add me to your contacts and e-mail me.

Answer 8

It's the friction between the object and the atmosphere. The velocity of the object is so great, that the Air slows it down dramatically. The friction is so great, it creates enough heat for ignition and burning.

Answer 9

Because they are going so fast.

Technically they don't burn. The high supersonic speed creates a shock wave in the air, compressing the air which heats it up. That heat can melt and even vaporize the object, but it isn't actually burning. And it is the speed in the air and not merely being in air that causes this. Meteors arrive at tens of thousands of miles per hour.

Answer 10

the extreme speed that they are moving is due to the general lack of matter in interplanetary space. when these objects run into the atmosphere, its like hitting a wall and the friction causes comustion.

Answer 11

Its because of Ram pressure. When an object comes down in the atmosphere, it compresses air in front of it. When pressure goes up, temperature goes up, and thus you have an effect of the 'burning off'.