On July 14th, 2015, NASA's New Horizons spacecraft made history. It was the first vehicle ever to visit and study Pluto up close — and nearly a year later, the mission is still providing amazing details about the dwarf planet. During its flyby, the probe came within 7,750 miles of Pluto's surface, gathering data about the tiny world and snapping detailed images along the way. And the spacecraft has been sending back all that data piece by piece over the past year, slowly crafting an intricate portrait of Pluto as a unique and active world.

To celebrate the one-year anniversary of the Pluto flyby, The Verge sat down with Alan Stern, the principal investigator of New Horizons, to discuss how the engineering team pulled off the mission and what it felt like on that monumental day.

"The right words just to say it was emotional."

"The right words just to say it was emotional," Stern told The Verge. "We had put so many years and so much of our lives into that, and in as much as you practice with ground simulations or with software simulations, as much as we tested it on the ground, we knew it came down to just one day."

Video by Miriam Nielsen