Researchers have found something in common with the atmospheres on Earth, Jupiter, Saturn, Uranus and Neptune; and it could help us find life in the universe.
As the altitude gets higher on Earth, the air cools down and thins out; but at a certain point it stops cooling and starts gradually heating up, a University of Washington news release reported. This phenomenon occurs at between 40,000 and 50,000 feet in the air.
Scientist Léon Teisserenc de Bort, who discovered the occurrence back in 1902, dubbed it the "tropopause." He named the region above the pause the "stratosphere" and below is the "troposphere."
In the 1980s NASA found a tropopause also existed on Jupiter; Saturn; Uranus; Neptune; and Saturn's famous moon, Titan. The tropopauses occurred in about the same place in the atmosphere as it does on Earth.
A new study suggests tropopauses exist in millions of thick-atmosphere planets and moons in the Milky Way.
"The explanation lies in the physics of infrared radiation," UW astronomer Tyler Robinson said in the news release.
Gas in most observed atmospheres tends to absorb infrared light that comes from either the planet's surface or its inner atmosphere.
The team used an analytical model to determine that at high altitudes with lower pressure the atmosphere becomes "transparent to thermal radiation."
When the pressure reaches 0.1 bar the infrared radiation causes the atmosphere to heat up. This information could help researchers further understand the climate on other planets.
"Then we have somewhere we can start to characterize that world," Robinson said. "We know that temperatures are going to increase below the tropopause, and we have some models for how we think those temperatures increase - so given that leg up, we can start to extrapolate downward toward the surface."
"It's neat that common physics not only explains what's going on in solar system atmospheres, but also might help with the search for life elsewhere," he said.
