Why NASA’s New Horizons voyage to Pluto and beyond is so cosmic

People of Earth:

Only rarely do you get the chance to explore a new world, so buckle up because the moment is approaching at a speed of 30,000 mph. That’s how fast NASA’s New Horizons spacecraft is hurtling toward its destination of tiny, distant Pluto. Just 60 million miles or so to go before the planned July 14 flyby — after a journey lasting more than nine years and 3 billion miles.

You remember Pluto, the once-beloved planet, smallest, maybe cutest of the nine with its oddball elliptical orbit, until it was kicked out of the band like a disrespected drummer. That happened in 2006 because it did not meet new criteria for planethood set by the International Astronomical Union. Pluto’s a dwarf planet now.

But let’s look past that insult to consider the science and meaning of NASA’s fantastic voyage. Pluto is the final major, unexplored destination in our solar system (well, that we know about). Scientists, and even curious grade-schoolers, know a lot about the other planets because NASA spacecraft have flown to each. They know less about Pluto, which has been viewed and studied only from afar.

The last breakthrough moment of this type was in 1989 when NASA’s Voyager 2 flew past Neptune, becoming the only object from Earth to visit planet No. 8. That spacecraft discovered four rings around Neptune and five moons, one of which, Triton, has a nitrogen ice volcano.

Voyager 1 and Voyager 2 continue to fly. They are way out in deep space now, but neither cruised past Pluto. So while there have been plenty of other astronomical discoveries since that visit to Neptune, there’s been no new world to conquer — until now.

“You think of Pluto as a dot of light,” Alan Stern, New Horizons’ principal investigator, or top scientist, told us. “It’s about to become a real world in living color.”

The first color photo of Pluto showed up last week, smudgy from a distance of 71 million miles. Expect a more exciting show when New Horizons arrives on the scene with its cameras, spectrometers and plasma and dust detectors, getting as close as 7,750 miles from Pluto’s surface. Some spectacular pictures should show up quickly, but it will take more than a year for New Horizons to transmit everything it records back to Earth. That will allow the spacecraft to devote most of its attention to gathering more data.

The cosmic dust-up over Pluto’s identity is still contentious in science circles, but what New Horizons is about relates to the big picture — the very big picture. What else is out there 3 billion miles from Earth and beyond? Will the inevitable discoveries again change the way we think about our place in the universe?

On its $700 million journey, managed by Johns Hopkins’ Applied Physics Laboratory, New Horizons will map the geology of icy Pluto and study its atmosphere and seasons. It also will look at Charon and the other four known moons that orbit Pluto. After that? Whoosh! Assuming funding is approved to continue the mission, New Horizons will head deeper into the Kuiper Belt, the mysterious neighborhood surrounding Pluto that spreads toward the outer edges of our solar system.

There are billions of comets out there in the Kuiper Belt, maybe 100,000 larger bodies and something like six to 60 other Pluto-like proto-planets. That’s why Pluto was downgraded in the first place. It turned out to be the most visible of many little floating objects that never congealed into something bigger.

The existence of the Kuiper Belt as we now understand it was confirmed only in 1992, giving New Horizons’ trip a cosmic context all its own: You can think of Pluto as the end of the line of recognizable heavenly bodies, or the gateway to this newly defined, little-understood region of our solar system.

That’s what makes this adventure so great. By following New Horizons on its incredible journey, we can stick out heads way above the clouds and ponder our place in the infinite heavens.