The New Horizons spacecraft's flyby of Pluto on July 14 is making the former planet come alive. High-resolution images have put a face on this once-mysterious world. We've probed its atmosphere and imaged its moons for the first time.
Icy peaks rivaling the Rocky and Appalachian Mountains slice through its lower atmosphere, and nitrogen glaciers have carved up its surface sometime in recent geological history. Can we call it a planet now? It depends who you ask.