One year ago this week, NASA’s New Horizon’s mission made its closest approach to Pluto, nine years after the mission’s launch in 2006. That mission shattered any misconceptions that scientists or the public might have had about dwarf planets, revealing an immensely interesting and complex world.
Although Pluto was demoted from full planetary status (it has been considered a dwarf planet since 2006), NASA said that exploring Pluto and its neighborhood, the Kuiper Belt, remained one of their highest priorities.
“The data that New Horizons sent back about Pluto and its system of moons has revolutionized planetary science and inspired people of all ages across the world about space exploration,” said Alan Stern, New Horizons principal investigator, in a NASA press release. “It’s been a real privilege to be able to do that, for which I’ll be forever indebted to our team and our nation.”
The New Horizons mission was the capstone to NASA’s decades-long effort to explore the solar system, as The Christian Science Monitor's Pete Spotts has highlighted. For 53 years, between Mariner 2’s Venus flyby in 1962, and New Horizon’s Pluto approach last summer, NASA has been gathering information on the planets of the solar system.
During that half century, our understanding of the solar system has grown explosively.
“It’s of fundamental importance for the survival of life on this planet that we know what our neighborhood is,” Jim Green, who heads NASA’s Planetary Science Division, told the Monitor last year.
From the beginning of its Pluto flyby last summer, New Horizons shocked scientists with images that revealed a more complex planet than they had expected. Pluto featured massive mountains and a dynamic geological past and present.
On Pluto, New Horizons discovered evidence that the dwarf planet’s atmosphere underwent great pressure changes over time, and that there may have once been some sort of liquid on the planet’s surface.
Images captured by New Horizons show an equatorial tectonic belt on Pluto’s moon, Charon, that indicates that Charon’s now-icy core was liquid long ago. Charon also has a red polar cap that may have been formed by escaped atmospheric gases on Pluto.
New Horizons surprised scientists when it sent back evidence that Pluto’s atmospheric escape rates were lower than expected, and that Pluto’s atmosphere is blue.
Information gathered by New Horizons also supports the theory that Pluto’s moons were formed by a collision between Pluto and another Kuiper belt object at some point in the distant past. Crater dating on the moons suggests that they are all the same age.
Finally, New Horizons made perhaps the sweetest discovery in the history of space exploration when it captured images of a heart-shaped nitrogen glacier on Pluto’s surface. At 1,000 kilometers across, the glacier is the largest known in the solar system.
And the era of Pluto discoveries isn’t over yet, as the spacecraft continues sending back data collected during last summer's flyby.
New Horizons is transmitting the information while traveling onward, as it continues to explore the distant realms of our solar system. Researchers say they don’t expect the groundbreaking science to end any time soon.
“New Horizons not only completed the era of first reconnaissance of the planets, the mission has intrigued and inspired. Who knew that Pluto would have a heart?” asked NASA’s Dr. Green in a press release.
“Even today, New Horizons captures our imagination, rekindles our curiosity, and reminds us of what’s possible.”