After more than nine years and 3 billion miles, NASA’s New Horizons probe flew by the dwarf planet Pluto Tuesday morning.

The project cost somewhere in the neighborhood of $700 million.

But John Logsdon, professor emeritus at the Space Policy Institute at George Washington University, says the cost is worth it when you think about what has just been accomplished.

“We sent this little spacecraft — it’s just the size of a piano, about 1,000 pounds — 3 billion miles. Hit a 60 by 90 mile target,” he says. “We’re seeing things that humans have never seen before. If that can’t excite people, what will?”

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