The NASA New Horizons spacecraft has taken robotic space exploration to the very outer regions of our solar system, and on July 15, 2015, it gave us our first close-up look of a completely new type of planet — an ice world. And, boy, were we surprised.
We saw a world that is dynamic and mysterious. We discovered that Pluto, 4.67 billion miles from Earth, is a world with glaciers made of solidified nitrogen (you are breathing nitrogen right now), mountains of water ice (the largest ice cubes in the solar system), plains covered by a thick layer of organic goo (it’s still unclear exactly what that is), an atmosphere with structures unlike anything seen elsewhere in the solar system, and even evidence of an interior ocean of liquid water. There’s some evidence for climatic changes that occurred over hundreds of thousands of years. And that’s just a sampling of the many discoveries made during the spacecraft’s flyby of that planet.
We should have learned this lesson well by now: The universe is always more complex, more diverse, and more bizarre than anything we can imagine or predict.