In July 2015, NASA's New Horizons spacecraft has captured a large, bright, somewhat-heart-shaped patch of mostly nitrogen ice on Pluto. The 1,200-mile structure has been named Tombaugh Regio, after the American astronomer Clyde Tombaugh who discovered Pluto in 1930.
Last summer, NASA has noted that the dwarf planet's heart borders dark equatorial terrains and the mottled area to its east is complex. Much of the heart's interior has appeared remarkably featureless, a possible sign of on-going geologic processes.
A study in Science journal Nature digs deeper into those so-called processes. Researchers have ran simulations that tracked 50,000 years both into the past and the future in order to see what formed the icy symbol and how it changed.
Authors Tanguy Bertrand tells Researchgate that the heart shape is created by highly volatile nitrogen ice that unavoidably accumulated in the basin and formed a permanent reservoir of ice. In addition, it is fascinating to note that the massive glacier that makes up much of the heart will change shape with time, enlarging and shrinking like a heart beating.
Pluto's heart is a large frozen plain which is informally known as Sputnik Planum. It is void of impact craters and the plain has been peppered with mysterious polygonal shapes between six and 38 kilometers in diameter.
To discover the origins of these polygons, computer models suggest that convection, or churning that arises from the rising and sinking of warmer and cooler matter, can explain the giant sizes of these cells. It must be noted that Pluto's innards are warmer than its surface because of heat from long-lived radioactive material.
According to William McKinnon, planetary geophysicist at Washington University in St. Louis, Nitrogen ice is not soft like a gummy bear which means that this matter is pliable than water ice on earth so it is convecting vigorously and forming these polygonal cells.
Scientists have estimated that convection likely leads the Sputnik Planum surface to renew itself around every half-million years which makes it one of the youngest surfaces in the Solar System.
