-457.9 °F

Nothing is too cold for ice. Ice can exist well down to absolute zero, and even possibly beyond. Nobody has ever seen it get too cold for ice. Ice can exist anywhere where it isn’t warm. And most of the universe is very, very cold. The Boomerang Nebula is the coldest known natural place in the universe. It reaches temperatures of 1 kelvin. It reaches temperatures of -457.9 degrees Fahrenheit. It is 5,000 light years away from Earth, in the constellation of Centaurus. It resembles a butterfly, or a bow tie, with a dark center that ejects two symmetrical glowing spotlight beams of gas and light on either side. This center is where you find the very extreme cold. It is a dying star, rapidly shedding its mass. The outflow of gas from its core drives rapid expansion, and that expansion creates frigid regions cooler than space itself. Space itself is incredibly cold, and getting colder. Space is expanding, and the energy density is decreasing. During the Big Bang, the entirety of everything was 18 billion degrees Fahrenheit, and it’s been cooling ever since. It’s been cooling and expanding, and today the background glow from the explosion — the cosmic microwave background radiation — is a chilling -455 degrees Fahrenheit. Just nearly as cold as those coldest regions of the Boomerang nebula. There may be colder regions that we don’t know about. Space is full of interstellar ice. Some of it is amorphous ice, meaning that instead of the crystalline structure we’re used to seeing on Earth, its particles are disorganized and random, much like liquid. It occurs at extremely cold temperatures, with its high-density state occurring at -207.4 degrees Fahrenheit. We are likely unaware of the full spectrum of forms ice can take, the magnitude of the temperatures that can exist, and the range of things that they can do to matter.