Why is it cold in space when the sun is hot?

Why is it cold in space when the sun is hot?

The sun is about 150 million miles away from the Earth, but we can feel its heat every day, and it's amazing how a burning object from a distance can emit heat at such a long distance.

We're not talking about temperatures that barely record his presence. In 2019, Kuwait's temperature reached 63 °C under direct sunlight. If you stand at these temperatures for a long period of time, you risk dying of heat shock.

But the most disturbing thing is that outer space remains cold, so why is space so cold if the sun is so hot?

To understand this surprising phenomenon, it is important to first recognize the difference between the two terms that are often used interchangeably: heat and temperature.

The role of heat and temperature

Simply put, it's warm.

This heat transfer can take place in three modes: conductivity, convection and radiation.

Heat transfer through conductivity occurs in solids. When particulates are heated, they vibrate and run into each other, transferring heat from hotter particles to colder particles.

Heat transfer through convection is a phenomenon observed in liquids and gases, and this heat transfer mode also occurs on the surface between solids and liquids.

When the liquid is heated, the molecules rise up and carry the heat with them. The room heater is the best example of a convective heat exchange.

When the heater heats the ambient air, the air temperature will rise and the air will rise to the top of the room.

Heat transmission through radiation is a process in which an object emits heat in the form of light; all materials emit a certain amount of thermal energy, depending on their temperature.

At room temperature, all objects, including us humans, emit heat in the form of infrared waves.

The hottest object, the more it will emit, the sun is a great example of thermal radiation that transports heat through the solar system.

Now that you know the difference between heat and temperature, we are very close to answering the question in the title of this article.

Now we know that temperature can only affect matter, but there aren't enough particles in space, and it's almost complete vacuum and infinite space.

This means that heat transmission is ineffective; heat cannot be transmitted by conductivity or convection.

Radiation remains the only option.

When solar heat in the form of radiation falls on an object, the atoms that form an object begin to absorb energy. This energy begins to move the atoms to vibrate and force them to produce heat during the process.

However, something interesting is happening to this phenomenon: because it is not possible to conduct heat, the temperature of objects in space will remain constant for a long time.

Hot objects remain hot and cold.

But when sun rays get into the Earth's atmosphere, there's a lot of stuff to excite, so we feel the radiation of the sun as heat.

This naturally raises the question: What happens if we put something outside the Earth's atmosphere?

Outer space can easily freeze or burn you.

When an object is located outside the Earth ' s atmosphere and in direct sunlight, it will be heated to about 120 °C. Objects around the Earth and in outer space that do not receive direct sunlight are within 10 °C.

The temperature of 10°C is due to the heat of some molecules leaving the Earth's atmosphere, but if we measure the temperature of the empty space between celestial bodies in space, it will only be three Calvins above absolute zero.

So the main conclusion here is that the temperature of the sun can only be felt if there's matter to absorb it, there's almost no matter in space, so it's cold.

Two Sides of Solar Heat

We know it's cold in the shaded areas, the best example is the night when the temperature drops because there's no radiation in this part of the Earth.

Yeah, objects that are hidden from solar radiation will be colder than stains that get sunshine, but the difference is pretty significant.

An object in space will face two extreme temperatures on both sides.

Let's take the example of the moon, the areas that receive sunlight are heated to 127 °C, and the dark side of the moon will be at a temperature of -173 °C.

But why does the earth not have the same effects? Because of our atmosphere, infrared waves from the sun are reflected, and those that enter the Earth's atmosphere are evenly distributed.

That's why we feel a gradual change of temperature, not extreme heat or cold.

Another example of the polarity of temperature in space is the influence of the sun on the Parker solar probe.

In April 2019, the probe was only 15 million miles away from the sun and used a thermal shield to protect itself.

The temperature of the thermal shield, when bombed by solar radiation, was 121 °C, while the rest of the probe had -150 °C.

Space is the best thermos.

When there's nothing to heat, the system's temperature remains the same, and so does space. Solar radiation can pass through it, but there are no molecules or atoms to absorb this heat.

Even when the rock is heated above 100 °C by the radiation of the sun, the space around it will not absorb any temperature for the same reason.

Hence, even when the sun emits, space remains as cold as ice!