Baby, It's Cold Outside

Coldest Place in the Universe

January 29, 2019
Our Cold Universe

It’s been a cold meteorological winter so far, and the northeastern states hit their very coldest point this past Sunday morning, January 7. If you want consolation, you might turn to the sky because the universe seems like a frozen emptiness to be avoided rather than explored.

Appearances, in this case, can be believed. The cosmos is a vast icebox punctuated by far-flung islands of unbearable heat.

These nights, Orion, now in the east every evening, has more fiercely hot blue stars than any other constellation. Regions that could be considered warm—not hot or cold, but comfortable—are so rare as to be essentially non-existent. Of course, we happily live on such a planet, the only example of moderation in the entire known universe!

What About Mars?

Even Earth’s arctic areas are far more hospitable to life than Mars, the most comfortable planet outside our own. Some visionaries dream of Martian colonies, forgetting it’s typically 100 below zero there, with no air to breath, and high radiation. Those volunteers you may have heard about, who are hoping to take a one-way trip to Mars two decades from now … well, good luck to them. And that’s the Red Planet, the friendliest of them all, which by the way will come extremely close to Earth this summer, and will light up the sky as a brilliant orange “star” almost capable of casting shadows.  

All other planets are either hotter than a wood stove or else are unimaginable deep-freezes. Nothing in between.

How Cold Is The Universe?

Not so long ago, space itself was thought to register absolute zero, meaning -459.67 degrees below zero F. which is the temperature where all molecular motion comes to a stop. Now we know that a five degree (Fahrenheit) temperature bathes the universe, the leftover heat from the Big Bang itself. So, perfect cold (to within a few billionths of a degree) only exists in two labs here on Earth.

This means that the coldest place in the known universe is right here.

And, stepping outdoors this past Sunday morning, it’s easy to believe.

About This Blog

Welcome to “This Week’s Amazing Sky,” the Almanac’s hub for everything stargazing and astronomy. Bob Berman, longtime and famous astronomer for The Old Farmer’s Almanac, will help bring alive the wonders of our universe. From the beautiful stars and planets to magical auroras and eclipses, he covers everything under the Sun (and Moon)! Bob, the world’s mostly widely read astronomer, also has a new weekly podcast, Astounding Universe