What is the temperature in space?
It depends on whether you are asking what is the temperature “of” space, or the temperature of things that are “in” space. Strictly speaking, space really doesn t have any temperature since it is mostly empty. Only things that can be found in space such as atoms and ions, have any temperature. Near Earth and the Moon, if you are in direct sunlight, you could heat up to 250 degrees F (121 degrees C). This is hotter than boiling water at 212 degrees F (100 degrees C). In the shade, it can cool to around -250 degrees F (-156 degrees C). This is why astronauts must wear thermal space suits.
A. Temperatures in space depend on whether the thermometer is in sunlight or darkness. Near the Earth and the Moon, objects in direct sunlight can heat up to temperatures of about 250 degrees F (121 degrees C). In the shade, objects can cool down to around -250 degrees F (-156 degrees C). This extreme range is the reason why the thermal designs of spacecraft and space suits are so important.
When calculating the temperature in space, it is important to understand that most estimates must take into account the varied makeup of space. Outer space is the portion of the universe which is almost entirely empty. Unlike the small pockets of our universe which are inhabited by stars, planets, and other large sections of matter, outer space contains very, very little. Nonetheless, it is not entirely empty, and this is important to understand when considering the temperature in space. The short answer is that the temperature in space is approximately 2.725 Kelvin. That means the universe is generally just shy of three degrees above absolute zero – the temperature at which molecules themselves stop moving. That’s almost -270 degrees Celsius, or -455 Fahrenheit. In one sense, we can talk about the temperature in space as being 2.725 K. This shifts a bit from place to place, but not by much more than a thousandth of a degree. For all intents and purposes, this is the generally accepted
By Steve Willner
I can imagine that it changes in our solar system relative to the distance from the sun but what about outside our solar system or galaxy, in the middle of nowhere? Does the universe have an average temperature? Does it get colder as the universe expands? Do solar systems keep heat in? Just a thought. — Henk The temperature of the universe is 2.725 +/- 0.002 degrees Kelvin. The Kelvin scale, for those who slept through high school physics, is the same as the Celsius scale, only it starts at absolute zero. In short, the universe is pretty cold. Fortunately, our Milky Way galaxy is about 0.0001 K toastier. Measuring the temperature of the universe isn’t as easy as you might think–you don’t just stick a thermometer into space and see the mercury shrink to the 3 K tick mark. We measure the temperature of the universe by using Planck’s famous black body radiation law, one of the first results of quantum physics. This law states that every object radiates electromagnetic energy according to
