For many years, the best-known image of dwarf planet Pluto looked vaguely like a golf ball. Hubble Space Telescope’s global computer imaging maps gave us the best pictures technology could do from three billion miles away. That changed with the fly-by of the New Horizons mission.

Launched in January 2006, the piano sized probe would take nine years to reach Pluto. During its flight, two more moons of Pluto were discovered, Kerberos and Styx, bringing the moon total to five, and raising concerns there might be orbiting debris that could harm the spacecraft.

On July 14, 2005, New Horizons successfully flew as close to the surface of Pluto as it would get and collect so much information it would take 15 months to download. Suprises were revealed in the new data. Findings showed a less dense world than imagined. One with mountain ranges of ice, glacial flows, possible plate tectonics, and a heart.

Pluto’s heart captured everyone’s heart. It was named Tombaugh Reggio, for Pluto’s discoverer, Clyde Tombaugh. A massive nitrogen glacier, Sputnik Planitia is the largest in the solar system. Covered in extremely reflective materials, it reflects more light than the surrounding areas. Sputnik Planitia’s left side is smooth and without craters, and the right side is full of jagged ice. The dipped basin region, a result of an ancient collision, is currently thought to be the heartbeat of Pluto’s climate.