Without any doubt, the single most amazing thing humanity revealed about Pluto during New Horizon's momentous flyby last year was that the dwarf planet had a huge heart. Not a real heart, mind you. Although, keep reading but a massive heart-shaped area, made generally of nitrogen ice. Now, thanks a lot to a new discovery, we now know how this area, named as Tombaugh Regio, might have come to be. One thing to realize about Pluto's heart is that it is not just ice, but a vast foundation of glaciers. And the ice in those glaciers is mostly made up of nitrogen, but there is also carbon monoxide and methane in the mix.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory
(UAPL)/Southwest Research Institute
But in what way did all these organized together to make the unique heart shape the world now knows and loves? Using NASA's New Horizons provided information and data and an epic recreation to model Pluto's atmospheric improvement over the course of some 50,000 years, scientists from the Université Pierre et Marie Curie in France have assumed us an answer.
Lead scientist Tanguy Bertrand told Maarten Rikken at ResearchGate, "Pluto's surface is an astonishing mix of different types of ice that do not exist naturally on Earth: methane, nitrogen, and carbon monoxide. We established a thermal model of Pluto's surface to understand the method of condensation/sublimation of its ice at an overall scale".
The smooth-looking left half of the heart, known as Tombaugh Regio, is a 1,000-kilometre-wide surface named as Sputnik Planum, and beneath all that ice, this enormous expanse is, in fact, a deep basin that extends 4 kilometers downwards. According to the scientists, that crater deeds as a kind of cold trap, gathering ice into its reaches, and in precise nitrogen and carbon monoxide.
To discover this, the scientists' simulation scattered nitrogen, carbon monoxide, and methane ices a little mm thick across the planet. With Pluto's high and low topography accounted for as part of the recreation, counting the depths of the Sputnik Planum basin and two other important craters, the scientists sat back and observed as the millennia flew by.
Tanguy Bertrand told ResearchGate, "Scientists found that the heart shape is to a massive degree formed by highly unstable nitrogen ice that inevitably accumulates in the basin and produces a stable reservoir of ice, as detected by New Horizons. This takes place because of nitrogen's solid-gas equilibrium. At the end of the basin the pressure of the atmosphere, and so of gaseous nitrogen is more, thus the ice temperature is higher than the outside. As a result, nitrogen wishes to condense into ice there. Carbon monoxide ice, which is also unstable to nitrogen, was also found in be totally sequestered with nitrogen in the basin."
As for methane ice, it is not limited to Sputnik Planum, and can be found in an ice that shelters both hemispheres of the planet, furthermore to its presence in the basin. The discoveries informed in Nature, mean that Pluto would not need a buried nitrogen reservoir to feed the Sputnik Planum glacier, as researchers believed earlier.
But the new study proposes something even more intense might exist on the dwarf planet, thanks to the sluggish movements in the frosty landscape in time with Pluto's seasons. And we do mean slow, one year on Pluto is equal to 248 Earth years, meaning seasons take some decades to come and go. But when they do, the deepest, coldest spreads of Sputnik Planum will remain ice-covered in time, while the lower areas in and around Tombaugh Regio will let more gas and ice movement.
The end conclusion, if you were to film a time interval video of Pluto over hundreds of years? A beating heart, guys.
Bertrand told Ria Misra at Gizmodo, "The half heart glacier lying inside is actually a huge glacier, which is not made by the periodic changes. It perhaps formed when the basin was made and will stay there in the future. Though, it possibly flows and withdraws over a few hundreds of km (like a heart beating) with time, corroding and shaping the mountains nearby it."
How amazing. Pluto, our hearts are melting for you too.