A Tour of Cosmic Temperatures
We often think of space as “cold,” but its temperature can vary enormously depending on where you visit. If the difference between summer and winter on Earth feels extreme, imagine the range of temperatures between the coldest and hottest places in the universe — it’s trillions of degrees! So let’s take a tour of cosmic temperatures … from the coldest spots to the hottest temperatures yet achieved.
First, a little vocabulary: Astronomers use the Kelvin temperature scale, which is represented by the symbol K. Going up by 1 K is the same as going up 1°C, but the scale begins at 0 K, or -273°C, which is also called absolute zero. This is the temperature where the atoms in stuff stop moving. We’ll measure our temperatures in this tour in kelvins, but also convert them to make them more familiar!
We’ll start on the chilly end of the scale with our CAL (Cold Atom Lab) on the International Space Station, which can chill atoms to within one ten billionth of a degree above 0 K, just a fraction above absolute zero.
Credit: NASA’s Goddard Space Flight Center/Scott Wiessinger