If the Sun Is Burning Hot, Why Isn’t Space Warm? — Here’s What Scientists Found

When you step outside during the day and feel the sunlight on your face or body, it’ll feel warmer. But if you go back inside or somewhere with a shade, it could suddenly feel a lot cooler. This happened even if the sun is still right up there in the sky as it has always been. Now, realizing this scenario, some people ask, if the sun is in space blasting energy and its sunlight in all directions, why isn’t space warm?

The space between planets and the sun is cold, but in our case, Earth gets warm when the sunlight reaches us, so why exactly are those vacuum gaps cold? What is the explanation behind it? Let’s find out.

Why is the Sun Hot, While the Space Around It is Cold as Ice?

On Earth, there are two main ways you could feel the warmth of the sun. First is through conduction and convection, where the air gets warmed, touches your skin, and then moves around. The other is through radiation, where the light and infrared rays of the sun are directly absorbed in your body.

So, in space, these two ways are not applicable to heat up the vacuum gap. There is no air, no wind, and only a few little particles spread out per cubic centimeter in many different regions. In other words, there is nothing like the Earth’s atmosphere that would be able to hold the heat.

Moreover, the sun still sends radiation and its visible lights and other electromagnetic energy, which is why the satellites and space stations up there get warm fast when they get hit by the rays. But, space itself does not have much to warm, and since heat is just energy in particles, and there are almost no particles, then there’s almost nothing to be warm.