If you release a rock, it will fall back down and enter earth's atmosphere because the gravitational pull of the earth is stronger than its potential energy. But, it will rise to a certain height.
After that, it'll be just like before and won't burn. So, an excellent question comes out: "Why does a thing burn up in the atmosphere?" We will explain this question's answer in more detail here.
Layers of the Atmosphere
The lowest region of the atmosphere, extending from the earth's surface to a height of about 3.7–6.2 miles (6–10 km), is the lower boundary of the stratosphere.
The troposphere is where all weather occurs. The troposphere contains 75% of the total mass present in the atmosphere. It extends from 3.7 miles to 10 miles above ground level and varies depending on its location.
The temperature decreases as you go up into it; at about 5-7 miles altitude, there is no ozone present, and it reaches a frost point where water vapor freezes out as ice crystals that form cirrus clouds which create high-pressure systems like anticyclones or cyclones for example.
The stratosphere is the region of the planet's atmosphere that extends from about 10 to 50 km above sea level. The stratosphere contains ozone and absorbs UV radiation from the sun.
This absorption of UV radiation by the ozone layer prevents most of it from reaching the Earth's surface, where it would be harmful to life.
Temperature increases with height in the stratosphere due to cooling by ozone. Jets like to fly in this region because there are more air atoms present which means that there's less drag.
The stratosphere is also home to many types of birds including swans, cranes, and vultures that are able to fly here because their bodies are designed for flight at large altitudes.
3. The Mesosphere
The mesosphere is the region of the atmosphere that is above the stratosphere and below the thermosphere. It has a very low density due to its large altitude and is colder than both regions.
The mesosphere also exhibits an inversion of temperature, which means that it's coldest near the top. This region doesn't have any permanent life, but it contains significant quantities of ozone.
4. The Thermosphere
The thermosphere is the region of the planet's atmosphere that starts at the mesosphere and ends at the outermost limit, called the exosphere. It is characterized by an increase in temperature with height, due to heating from the direct absorption of solar radiation.
The lower part of this region is also protected from atmospheric drag, so it accumulates dust particles within its magnetic field. That way, it becomes a source of air pollution.
Due to the increased temperature with height, this region emits auroras and meteor showers at night time, while it absorbs some types of radiation, which are denoted by gamma rays.
Furthermore, it contains atomic oxygen gas atoms that are heated by ultraviolet light from below and can catalyze ozone destruction.
The Exosphere is the final frontier of Earth's gaseous envelope. It extends from 190,000 km (120,000 miles) to infinity and has no clear-cut upper boundary where it finally fades away into space.
The exosphere is home to meteors and auroras at night time while absorbing some types of radiation like gamma rays. This region contains atomic oxygen gas atoms that are heated by ultraviolet light from below and can catalyze ozone destruction.
Due to the increased temperature with height in this region, it emits auroras at night time while also protecting itself with a magnetic field against atmospheric drag, which accumulates dust particles within its magnetic field, becoming an air pollutant source.
6. The Ionosphere
The ionosphere is a part of earth's upper atmosphere, which starts at about 80 km and extends up to 600 km. It is part of the earth's electromagnetic sphere, and it interacts with solar radiation. The ionosphere reflects radio waves back to earth, thus creating communication and navigation possibilities.
Why do Things Burn Up in the Atmosphere?
There are a few reasons why things burn up in the atmosphere. These reasons are:
Reason 1: Atmospheric heating
The air around the object is heated. You may know that hot air rises and cold air falls. The heat energy of the molecules in an object changes their momentum and when this happens, it causes turbulence in the surrounding atmosphere (the planet's "weather").
This turbulence heats up the surface of an object because these hot parts collide with other objects that are falling at the same velocity.
Reason 2: Shock Waves
When a thing travels faster than sound, it creates shock waves around it. These pressure waves change the flow of air around the object. They can cause an area behind or in front of the moving body to compress and expand very quickly.
This extremely quick compression and expansion heats up the air, which in turn heats up the thing and it flams. We all know that when something moves at a huge velocity, it gets very hot because of its motion and the heating is a result of this compression and expansion.
Reason 3: Velocity
As a thing moves faster, the air molecules in front of it have less and less time to get out of its way. They keep piling up in front of it and when they collide with each other, they heat up the object and flame it. This is because when something speeds up, its kinetic energy increases too.
Reason 4: Re-entry angle
An item moving through the atmosphere depends on its direction or trajectory. If a thing is coming towards the earth, it has to go faster than if it was just hovering and flamed. A thing that hits the atmosphere at a shallow angle and will be burning up less because it isn't traveling as fast.
Reason 5: Ionization
The atmosphere of the earth is made up of several fuels like Oxygen and Nitrogen that can easily be ionized. As a thing gets closer to the atmosphere, it begins to accumulate a charge.
This happens because as the molecules rub against each other (or "collide"), charges are transferred from one molecule to another.
When the thing and the atmosphere collide, they cause a change in momentum which leads to turbulence. This ionization can lead to an imbalance of electric charge between the thing and the atmosphere, causing a powerful electric field to build up.
This electrical potential can accelerate ions across the gap at speeds approaching the speed of light, causing them to release energy and heat. That's why that thing is flamed.
1. At What Speed do Objects Burn Up in the Atmosphere?
Answer: Objects burn when they reach the upper layers of earth's atmosphere because of collisions with the various gases of the atmosphere.
The sun's ultraviolet radiation and solar winds cause ionization, which leads to air atoms being split into their component parts: electrons and ions, with each having a positive or negative charge.
When these charged particles are released, they attach themselves to other particles, causing them to be electrically charged as well - this is why you can see lightning when there's a storm in your area!
Meteors enter earth's atmosphere at higher speeds, about 10 km/h second or 36 thousand km/h.
2. Can You Enter the Atmosphere Without Burning Up?
Answer: If you are going slow enough, you might be able to hit the air without burning up. The slow speed acts as a heat shield at that time. However, if your speed is faster than 10 kilometers per second (or 36 thousand km/h), you are definitely going to combust.
3. Why don’t Things Burn Up When Leaving the Atmosphere?
Answer: The coming things are faster than sound, so it works like a heat shield. This speed keeps the objects from combusting.
4. Why don't Skydivers Flare Like Meteors?
Answer: It is because skydivers are not at the speed of sound or higher, so they do not flame up when they enter the atmosphere. Skydivers fall at an average speed of 120 mph (between 110 and 130 mph), which is not fast enough to cause a fire.
5. What Generates All the Heat During Re-entry When the Space Shuttle Returns to Earth?
Answer: It happens because of the atmospheric gases, which are heated up by the shuttle's speed.
6. Why don’t Airplanes Combust when they Fly Over Oceans or Mountains?
Answer: Airplanes can fly up to 7.2 miles above water. Normally, smoldering fires need a supply of molecular oxygen drawn directly out of the environment. The height where there are insufficient resources for this becomes less than around 18 km(11 mi) above sea level.
Space doesn't have a climate. In fact, the lack of atmospheric pressure in outer space causes materials to flame up at a much quicker rate than on earth because there's no air to slow down the process.
We hope you got your question’s answer and also learned something new in this blog post and that it has empowered you to do your part in protecting the planet's environment.