APOD 2.7

How cold can Earth possibly get?

Or how about: how cold can it get on the coldest place on Earth?

The first place a lot of people think of when you ask that question is the Antarctica and that is right. Well, measured on July 31, 2013, the interior of Antarctica can be as low as -135.3 degrees Fahrenheit! Yes, that is very, very, very, cold. This temperature was taken near the mountain peaks in the area just because it is generally colder the higher you go.

Why?

Well, the less air pressure there is the colder something is. Take spray paint for example. When you spray paint something and then you touch the bottle, it feels cold. That is because you are releasing the pressure inside the bottle. Let's think about it in another way. Air has particles. Each particle has loads of energy. When you put a couple of particles of air near each other in a sealed compartment they begin to bounce off the walls of the compartment and with one another. When something is moving very fast then it tends to release heat because the energy is coming off as heat. Now picture yourself trying to compress millions of trillions of moving, energized air particles into a 16 ounce metal bottle. Now that is some pressurized air! You see once you press down on the nozzle and let out the air, you then relieve some of the pressure inside the bottle and because that much air is lost from the bottle then then are less air particles moving and bouncing around so there is less heat being made.

Now how is this possible in a place as big as Earth?

First off, I think we can all say that Earth has a gravitational pull on things. The closer you are to the core of the Earth, the stronger the gravitational pull. Therefore, the farther you are from it, the less the pull impacts things. Now the way that I think of it is that the gravitational pull closer to the ground pulls the air closer to the Earth which is why ground level has a higher pressure than on a mountain top. This is also why people say that the bottom of the ocean has such high pressure, because of the great gravitational pull! Now the reason why the Antarctic is colder than the highest mountain in the world is also because there is less sunlight shining down at the bottom of the Earth. Just be grateful that you are not down there right now because personally, down here in Florida, 60 degrees is cold enough for me!