How New Horizons Changed Our View of Pluto (Literally)

By Joy Powers

Published December 1, 2016 at 8:45 AM CST

This high-resolution image captured by NASA’s New Horizons spacecraft combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera (MVIC).";

Every few years, it seems we’re treated to photography from outer space that gives us a brand-new perspective on the universe. Missions like the Mars Pathfinder, with its Sojourner rover, have allowed people to see places humans will probably not experience in the near future – though they might, someday.

Scientist John Spencer (in glasses, at computer), along with principal investigator Alan Stern (to his left) and others, react as images come in from New Horizon's 2015 Pluto fly-by.

But last summer, we saw remarkable pictures of a place that humans are unlikely ever to set foot. The New Horizons mission sent back the first-ever pictures of Pluto to show any detail of the dwarf planet.

"We had no idea what Pluto looked like up close," says scientist John Spencer of the Southwest Research Institute, a member of the New Horizons team. "The best pictures we had were like, three pixels across; just really fuzzy. And now we have pictures that are five thousand pixels across, just incredible detail. So we had no idea of the landscape and we never imagined it would be this diverse and exotic and fascinating as it's turned out to be."

Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon.

The details in the photos were breathtaking and included images of mountains, glaciers, and even an atmosphere. "We've learned that Pluto is an amazingly complex world for being such a little place," says Spencer. "It has vast seas of nitrogen, glaciers, frozen nitrogen that's flowing on the surface and is bubbling up from below, from heat from below."

Scientists with NASA’s New Horizons mission have assembled this highest-resolution color view of one of two potential cryovolcanoes spotted on the surface of Pluto by the New Horizons spacecraft in July 2015.

Still, there are a lot of things about Pluto that remain unknown. Although many elements of the planet are familiar, like flowing glaciers and volcanoes, scientists are unable to explain how some these features came to exist.

"There are things that we still don't understand at all," says Spencer, who was in Milwaukee to speak at Marquette University. "There are huge mountains on Pluto; we're still scratching our heads as to how those formed. Some of them look kind of like volcanoes, but we've never seen volcanoes that look like that before."

Research on the dwarf planet is only just beginning, but for now, New Horizons is onto - well, new horizons. Next stop: an object in the Kuiper Belt, playfully named "2014 MU69." The team plans to reach it by January 1, 2019.

This piece was originally published October 5, 2016.