By Ashley Strickland, CNN

ATLANTA — A huge heart-shaped feature on the surface of Pluto has intrigued astronomers since NASA's New Horizons spacecraft captured it in a 2015 image. Now, researchers think they have solved the mystery of how the distinctive heart came to be — and it could reveal new clues about the dwarf planet's origins.

The feature is called Tombaugh Regio in honor of astronomer Clyde Tombaugh, who discovered Pluto in 1930. But the heart is not all one element, scientists say. And for decades, details on Tombaugh Regio's elevation, geological composition and distinct shape, as well as its highly reflective surface that is a brighter white than the rest of Pluto, have defied explanation.

A deep basin called Sputnik Planitia, which makes up the "left lobe" of the heart, is home to much of Pluto's nitrogen ice.

The basin covers an area spanning 745 miles by 1,242 miles, equivalent to about one-quarter of the United States, but it's also 1.9 to 2.5 miles lower in elevation than the majority of the planet's surface. Meanwhile, the right side of the heart also has a layer of nitrogen ice, but it's much thinner.

Through new research on Sputnik Planitia, an international team of scientists has determined that a cataclysmic event created the heart. After an analysis involving numerical simulations, the researchers concluded a planetary body about 435 miles in diameter, or roughly twice the size of Switzerland from east to west, likely collided with Pluto early in the dwarf planet's history.

The findings are part of a study about Pluto and its internal structure published Monday in the journal Nature Astronomy.

Recreating an ancient 'splat' on Pluto

Previously, the team studied unusual features across the solar system, such as those on the far side of the moon, that were likely created by collisions during the early, chaotic days of the system's formation.

The researchers created the numerical simulations using smoothed particle hydrodynamics software, considered the basis for a wide range of planetary collision studies, to model different scenarios for potential impacts, velocities, angles and compositions of the theorized planetary body's collision with Pluto.

https://www.ksl.com/article/50985174/pluto-gained-a-heart-after-colliding-with-a-planetary-body