The coldest place in the universe is not your ex’s heart. Scientists have actually been studying what used to be considered a hole in the sky known as Barnard 68, only to find out it’s actually a dark molecular cloud.
Molecular clouds are a type of interstellar cloud where molecules can form, most commonly molecular hydrogen. They make up the densest part of the interstellar medium and comprise almost one half of the total gas mass in the interior of the sun’s orbit.
In Barnard 68, the high concentration of molecular gas and dust absorb almost all of the visible light from surrounding stars, which makes it appear as if there is actually a hole in the sky. Measurements place Barnard 68 at roughly 500 light-years away.
The interior of Barnard 68 is one of the coldest places in the universe, reaching temperatures of -263 degrees Celsius. That’s just ten degrees above absolute zero. Absolute zero is the point at which no more heat can be removed from a system.
To put it in perspective, scientists have theorized that if a molecular cloud like Barnard 68 was placed in front of the sun there would be eternal darkness on Earth. Even though they’re just a clouds made of gas, their matter makes them so thick that even light waves can’t pass through.
One article calls molecular clouds “the nurseries of stars and planets,” and says that “to understand them is to understand the process that took place when the Solar System was formed about 4,500 million years ago.”
Scientists can use an infrared light to look through Barnard 68, which allows them to see all of the stars hidden behind it. These stars only aren’t visible to us because the gases inside the cloud obscure all visible light waves.
It isn’t yet known how molecular clouds like this one form, although it’s known that they were key in the formation of the universe and continue to be important in the process of creating new stars. Scientists believe it’s even likely that Barnard 68 will collapse on itself and become a new star formation.