Pluto’s Atmosphere Surprisingly Robust Despite Distance From Sun

May 15, 2020 Topic: Space Blog Brand: Techland Tags: SpaceNASAPlutoTechnologySolar System

Pluto’s Atmosphere Surprisingly Robust Despite Distance From Sun

When it comes to atmospheres, tiny Pluto is more resilient than you think.

When it comes to atmospheres, tiny Pluto is more resilient than you think.

Research has shown that the dwarf planet’s thin atmosphere is generated by the sunlight-driven vaporization of surface ices. The intensity of this vaporization differs greatly during its elliptical, 247-year-long journey around the sun.

As a result, many scientists believed that Pluto’s atmosphere rises and falls dramatically—perhaps even collapsing completely when it is at its farthest point from the sun.

However, recently published results in the journal Icarus, based on keen observations by NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), are bringing new counterintuitive ideas to the table.

“Pluto is a mysterious object that is constantly surprising us,” the study’s lead author Michael Person, of MIT’s Wallace Astrophysical Observatory, said in a press release.

“There had been hints in earlier remote observations that there might be haze, but there wasn’t strong evidence to confirm it really existed until the data came from SOFIA. Now we’re questioning if Pluto’s atmosphere is going to collapse in the coming years—it may be more resilient than we thought.”

Studies have shown that Pluto’s atmosphere is mostly nitrogen, with some methane and carbon monoxide, which exist in equilibrium with ices on the surface. The dwarf planet has a hazy blue atmosphere, where methane and other gases react to sunlight and rain down on the surface.

Scientists, though, wondered about what would happen to Pluto’s atmosphere when there isn’t enough solar insolation. At those great distances from the sun, atmospheric particles would not be replenished by the melting of the icy surface.

Apparently, there is no danger of atmospheric collapse, according to the new study. The atmosphere instead goes through cycles of loss and gain that can last several years, which are distinct from its 247-year orbit around the sun.

According to researchers, this data points to the fact that tiny particles in the atmosphere are created rather quickly—and that changes in Pluto’s orbit are responsible for this cycle, not just the distance from the sun.

Because of Pluto’s highly elliptical orbit, some surface areas receive more solar insolation than others at different times. When volatile ices are exposed to the sun, the atmosphere expands quickly and creates more haze particles. The reverse also has been shown to be true. This cycle has continued even when Pluto becomes more distant from the sun.

“There’s still a lot we don’t understand, but we’re forced now to reconsider earlier predictions,” Person said. “Pluto’s atmosphere may collapse more slowly than previously predicted, or perhaps not at all. We have to keep monitoring it to find out.”

Ethen Kim Lieser is a Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV. He currently resides in Minneapolis.

Image: Reuters.