The planet's core has been cooling for billions of years but perhaps "more rapidly than expected," which could expedite the end of life on Earth — though not for quite a while.
Earth's core is cooling faster than previously thought, researchers said this week, which could lead to the planet's inevitable march to desertion millions or even billions of years from now.
Earth's interior has been cooling slowly for the entirety of its 4.5 billion year existence - a generally helpful pattern as the planet evolved into its current green paradise, where humans have thrived for the past 200,000 or so years.
"This perspective raises the question of how fast Earth has been losing heat over Earth's history, which directly links to the fundamental question of how long Earth will remain dynamically active," the scientists said in a paper published in the journal Earth. written. and planetary science papers.
But how fast this process is happening is a matter of research.
A group of scientists studied bridgmanite, a common conductive mineral found between Earth's core and mantle.
They found that it is 1.5 times more conductive than previously thought, meaning Earth's cooling process may also be faster than previously thought.
The researchers said, "We found that the bulk thermal conductivity at the core-mantle boundary exceeds the traditionally predicted value by 1.5 times, supporting a higher heat flux from the core, hence more vigorous mantle convection than expected. "
"The results suggest that the mantle is cooled more efficiently, which will ultimately weaken many of the tectonic activities driven by mantle convection at a faster rate than would be expected from conventionally assumed thermal conduction behavior."
When the planet cools, it will lose its magnetic field, which protects Earth from harmful cosmic radiation. At that point, the Earth would become a sterile, uninhabited rock.
The researchers did not jeopardize the estimate of how many more years life could exist on Earth.
A 2013 launch by Andrew Rushby of the University of East Anglia in the United Kingdom estimated Earth's viability for life to be good for another 1.75 billion to 3.25 billion years, assuming there was no nuclear holocaust, rogue asteroid or other Not an unexpected disaster.