How cold is it in deep space?

As you probably know, space is already very, very cold — roughly 2.7 Kelvin (-270.45 Celsius, -454.81 Fahrenheit). This is mostly due to a lack of atmosphere and the vacuum-like nature of space — with very few molecules to energetically bounce around, there can be no heat.Feb 3, 2014 read more

That’s a nonsense question. It’s only when you put a thing in space, like a rock, or an astronaut, that you can measure temperature. read more

The temperature in deep space is 2.725 Kelvin. That’s just 2.725 Celsius above absolute zero, which is the coldest anything can be (it only occurs when there is no energy at all in the system; its physically impossible). read more

That question is sure to prompt the geeks among us to pipe up with “2.7K”. For 2.7 Kelvin, or 2.7 degrees above absolute zero, is the temperature produced by the uniform background radiation or “afterglow” from the Big Bang. But hang on. read more