Ex-planet Pluto slowly turning to ice as atmospheric gas presence diminishes: Study

Marking a new discovery, astronomers have now found that Pluto, the former ninth planet of our solar system is slowly losing its atmosphere. Experts suggest that its atmosphere, which mostly comprises nitrogen, methane and carbon monoxide is slowly turning back into ice. This decrease in atmospheric density is being accredited to Pluto’s growing distance from the sun as it is drifting further away from the solar system. 

What’s in Pluto’s atmosphere?

The atmosphere of this dwarf planet is largely made of nitrogen, but the presence of methane and carbon monoxide has also been confirmed. Till now, Pluto’s atmosphere has been maintained due to the vapourised gases formed because of the heat they received from the sun. These gases are mostly nitrogen emitted from the biggest known nitrogen glacier on Pluto called Sputnik Planitia, which can be spotted on the planet’s western part of the Tombaugh Regio area, as per Science Alert. However, over the years, scientists have confirmed that the atmospheric density of Pluto has been found to be decreasing.

What is causing the decrease?

The experts traced the atmospheric decline using ‘occultation’, a method that utilises light coming from a distant star as a backlight for Earth-based telescopes. Texas-based Southwest Research Institute's (SwRI) planetary scientist Eliot Young revealed that this method is being used on Pluto since 1988. As of now, the constituent gases have been found to be turning back into ice due to lack of sunlight as Pluto is being pushed further away from the sun. As per Science Alert, in 2015, scientists found a boost in the atmospheric density after studying data of a flyby conducted during the New Horizons mission.

A phenomenon called ‘thermal inertia’ was accredited for this boost where the sun’s residual heat was trapped inside Pluto’s glacier. However, the scientists have now confirmed from the database of 2018, that this increasing trend has witnessed a dip, and that is due to increasing temperatures, resulting from less sunlight in the dwarf planet.

Missions like the New Horizon have revealed that Pluto does house snowcapped mountains and oceans, data of which can greatly help the scientists in knowing more about its atmosphere. For those wondering how far Pluto sits, the planet takes 248 years to complete one orbit around the sun.

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