Scientists prepare for close-up look at Pluto

With each passing day, mankind gets a better look at Pluto. And each day, Pluto is showing mankind it has a lot to learn.

First, Pluto revealed itself in a mix of beige and orange, while Charon, its largest moon, appeared gray when the New Horizons spacecraft captured color images of the dwarf planet in early June. Then, scientists at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, spotted unusual dark poles on Charon. In late June, they saw mysterious dark streaks spaced evenly along half of Pluto’s equator.

New Horizons will pass within 7,800 miles of Pluto on July 14 after a nearly decade-long, 3 billion-mile journey. As the spacecraft nears that close encounter, the scientists are getting one never-before-seen look of Pluto after another. They expect to make daily revelations of new discoveries — and new questions — over the next week and a half.

“A few weeks ago, the faucet hadn’t turned on,” said Alan Stern, principal investigator for the $700 million NASA mission. “Now it’s dripping a little every day. Soon it’ll be a rush.”

New Horizons’ seven instruments are probing Pluto for evidence of its composition, terrain and atmo- sphere. While they began observing the dwarf planet this year, teams at the Hopkins lab are preparing for their most intense — and valuable — period of data collection.

The scientists have worked since 2009 on the plan for the final days of the journey to Pluto, when it will intensely observe the distant planetary dwarf.

When New Horizons makes its closest approach to Pluto, the mission will be out of the scientists’ hands — there will be a 22-hour period during which they won’t be able to contact the spacecraft until the pass is complete. The spacecraft cannot observe and communicate at the same time.

“We have to trust that it’s doing what it needs to do,” said Alice Bowman, the mission operations manager.