Meteor (flying rock) gets broken apart by air?
In: Physics
Imagine you are jumping in the pool, it doesnt hurt you, right?
Now imagine you are jumping in a pool from a 5meter/15feet tall spring/diving board and land on your belly.
Thats gotta hurt a lot.
Due to your higher speed the impact on the water is much more critical. What you feel is the density difference between gaseous air and liquid water.
For meteors its the same with earth.
They are flying extremly fast through the emptiness of space. There is nothing that could slow them down.
And then they hit the gaseous atmostphere of earth, which has a much higher density that space. You suddenly hit molekuls and material. And you do that at such a high speed that the atmosphere creates very high friction on the meteors and it will burn.
You would also burn if you would run with 15-20,000 km/h through the atmosphere.
So dont do that
Unlike space, where there is no air. Earth’s atmosphere has air. This air enables the creation of friction between the object and the air itself. This friction generates enough heat to destroy the object.
When you hit air really really hard, the air hits you really really hard back. Not only this, but the air generates a lot of heat as it is compressed by you hitting it really really hard. This heat will likely transfer to you, cooking you in no time flat. It is worth remembering that meteors are not solid bricks of granite most of the time – they’re loosely packed lumps of dust and small rocks.
Have you ever stuck you hand outside the window of a car driving down the highway?
You will have felt that the air going past was pushing at your hand and that the faster you move the harder the air pushes at your hand.
Sticking something light and fragile like a cheap paper flag outside the window of a fast moving car, will result in the object being ripped apart by the forces of the air rushing past.
Now imagine sticking something out of your car window when your car moves really really fast. That fast moving air will carry quite some force.
Objects coming down from orbital speeds move extremely fast. The International space station for example moves at speeds that would be something like 22 times the speed of sound if it were moving that fast near the ground.
At that speed the air will not really be able to move out of the way much at all. It will drag and tear at any tiny imperfections of the objects surface with enormous force. It will also heat things up with friction a lot. This sort of thing can for example rip apart a space shuttle coming down from orbit and turn it into a fireball.
So running into our planets atmosphere at high speeds can be a very destructive experience even for solid objects that were designed to withstand this kind of thing.
This brings us to the second part.
Many of the things out there are not very solid. There are snowballs and heaps of loosely stuck together gravel and things that even if you gently teleported them down to the surface and set them down without disturbing them would collapse under their own weight into a heap of material rather than remain stuck together as solid rock.
Of course there are also more solid obejects, but tumbling through the air at high speeds while being heated up red hot is not going to be doing them any favours either.
So when a meteor comes into Earth’s atmosphere it is broken up by the air. Specifically it’s the DENSITY of the air. With the speed of the rock and this density of the air, these combined creates a resistance causing it to break apart. Essentially, air becomes denser the closer you reach sea level. Air is considered a fluid in a bunch of disciplines. In comparison, the atmosphere is like the ocean. The closer you travel to the center of the Earth the density will increase for air and any body of water.
Edit: more explanation.
These rocks can by travelling at kilometers PER second. Hitting our atmosphere at those speeds causes friction and heat to build up very rapidly causing them to explode. It’s like when the shuttle used to reenter earth’s atmosphere and the flames would engulf it and it was travelling at a much slower speed.
Because a meteor is traveling at astonishing speed, around 100,000 miles per hour. Hitting even air at that speed will smash anything.
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