Pluto Shows Off Possible Ice Cap as New Horizons Closes in

NASA's spacecraft New Horizons is quickly approaching the small and icy world of Pluto, and already it is offering us a never-before-seen perspective. As it closes in for a historic fly-by in mid-July, the spacecraft can already see what experts suspect is a broad and bright polar ice cap.

"As we approach the Pluto system we are starting to see intriguing features such as a bright region near Pluto's visible pole, starting the great scientific adventure to understand this enigmatic celestial object," John Grunsfeld, the associate administrator for NASA's Science Mission Directorate in Washington, announced Wednesday. "As we get closer, the excitement is building in our quest to unravel the mysteries of Pluto using data from New Horizons."

The latest revealing images of Pluto, which is classified as a dwarf planet - much like the mysterious Ceres - were snapped between April 12 and 18 using New Horizon's Long Range Reconnaissance Imager (LORRI), as the spacecraft's distance from Pluto decreased from a whopping 69 million miles (111 million kilometers) to 64 million miles (104 million kilometers) away. (Scroll to read on...)

Also seen in these images is Pluto's largest moon, Charon, rotating in a painfully slow orbit that takes 6.4 Earth days to complete. And while the Texas-sized Charon was already clearly visible even back in January (when New Horizons was nearly twice as far away from its quarry as it is now), Pluto's other four moons are still too small to be seen. That's because they reflect far too little light for the LORRI to pick up.

Earlier in April, New Horizons also drew close enough to start snapping its first color photos of Pluto, revealing that Pluto is noticeably brighter than its moons and boasts a reddish hue. The reason for this remains uncertain.

"After traveling more than nine years through space, it's stunning to see Pluto, literally a dot of light as seen from Earth, becoming a real place right before our eyes," said Alan Stern, New Horizons' principal investigator at Southwest Research Institute in Boulder, Colo. "These incredible images are the first in which we can begin to see detail on Pluto, and they are already showing us that Pluto has a complex surface."

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