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The strange science of Pluto and space exploration

A picture of Pluto made available by NASA.
A picture of Pluto made available by NASA.EPA

Shortly before 8 a.m. Tuesday morning, NASA's New Horizons spacecraft flew past Pluto, capturing exquisitely detailed pictures of the not-quite planet and gathering vital information about its makeup.

At least, that's what we think happened. The craft is so busy gathering information that it won't check in until later Tuesday evening. And it'll be even longer before we get to see the photos, likely Wednesday afternoon.

The tremendous distance separating Earth and Pluto has created a gap between what's happening there, at the edge of our solar system, and what we can know about it here.

Sky-watchers and scientists are waiting impatiently for information from New Horizons, and the very fact that we have to wait tells us a great deal about the unique adventure that is space travel: the great distances that must be overcome, the creation of a perspective from outside humanity, and the breakdown of our telephone and Internet-driven sense that communication can be instantaneous.

What is this New Horizon mission all about?

When New Horizons was first launched, back in 2006, its goal was to gather detailed information about the least-understood planet in our solar system.

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A lot has happened in the ensuing 9½ years: A new US president, the rise of Taylor Swift, cellphone cameras with a higher resolution than New Horizons can boast, not to mention the demotion of Pluto to second-tier dwarf planet.

But the mission has continued unchanged, with New Horizons traveling for 9½ years for this week's rendezvous with Pluto and its moons.

How far has New Horizons traveled?

Currently, New Horizons is about 3 billion miles away from earth. That's 30 times farther than the distance between the Earth and the sun.

To put that distance in perspective, if you wanted to reach Pluto in your car you would need to drive for almost 6,000 years. In a plane, it would take 600 years. New Horizons made the trip in a mere 9½ years, traveling at an average speed of 35,000 miles per hour.

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Even if you could travel at the speed of light, it would still take 4½ hours to get to Pluto.

When did New Horizons pass Pluto?

Early Tuesday morning. But we won't see the pictures until Wednesday afternoon, and it will take months to retrieve all of the information.

When you're 3 billion miles away, sharing is hard. New Horizons can't send information any faster than the speed of light, meaning that each bit of information will take at least 4½ hours to reach us. And there's no high-speed Internet from Pluto, so you can't send lots of bits all at once. Scientists will need months to download all of the high-resolution images and other details.

Waiting on slow-traveling news from New Horizons puts humanity in a strange situation, where close-up pictures of Pluto exist — but not for us.

It's a throwback to a time before the Internet, telephones, and the telegraph. When information wasn't instantly accessible, and travel times made a substantial difference in what people knew and when they knew it.

The classic example is the 1815 Battle of New Orleans, which was fought after a peace treaty had already been signed in Europe — but before news of the war's end could reach armies in the United States.

Might these pictures restore Pluto’s place among the planets?

It's certainly possible that New Horizons will unearth data that strengthen the case for Pluto to reclaim its place among the planets. Already, the spacecraft has sent back the most detailed picture of Pluto ever taken — snapped in the days before the flyby. And from its preliminary data we've learned that Pluto is bigger than previously thought.

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Whatever New Horizons discovers, however, the bigger issue is that Pluto is surrounded by lots of other similarly sized bodies inside the ring of frozen objects called the Kuiper Belt. Traditional planets tend, instead, to be far larger than everything else in their orbit.

These frozen bodies are New Horizons' next targets. Once the spacecraft has flown past Pluto and its moons, New Horizons is headed toward more distant objects in the Kuiper Belt, in hopes of better understanding the outskirts of our solar system.

After that, sometime around 2020, its mission will be over. New Horizons will simply drift out to deep space, edging ever-farther away as its systems decay and it loses its ability to communicate with Earth.


Evan Horowitz digs through data to find information that illuminates the policy issues facing Massachusetts and the United States. He can be reached at evan.horowitz@globe.com. Follow him on Twitter @GlobeHorowitz