When was the last time you saw an image of Pluto? Think about it. You've probably seen renders and simulated images – but what about an actual, high-quality picture of the minor planet's surface? Don't feel bad if you're drawing a blank. Real pictures of Pluto just don't exist – none more than a few pixels in size, at least. Even with the best and most modern technology at our disposal today, we still can't produce a decent picture of the dwarf planet from here on Earth.
But around this time next year, thanks to the New Horizons spacecraft launched in 2006, we'll finally catch our first high-quality glimpses of how the solar system's most distant celestial object actually looks.
The best pictures we currently have of Pluto date from 1994.
If you can believe it, the best pictures we currently have of Pluto date from 1994. And, really, they're only pictures in the most liberal sense: blurry, blown-up surface maps made from source images mere pixels across. Taken with the Hubble Space Telescope, the orbiting camera is only just powerful enough to resolve the planet's surface colour – "a complex-looking and variegated world with white, dark-orange and charcoal-black terrain" – making geological observations out of the question.
"To a close approximation, Pluto and the moon are the same size." explains Dr. Marc Buie, a staff scientist at the Southwest Research Institute, and part of the team that captured the planet's first Hubble images. "[But] Pluto is an awful lot farther away."
In fact, from our planet's surface, Pluto is about 180,000 times smaller on the sky at that distance than the Earth's moon.
That hasn't given researchers much to go on – not in the visual wavelength, anyhow. But as you read this article, the New Horizons spacecraft is nearly 30 astronomical units from the sun – or, about the distance from the sun to earth multiplied by 30. Travelling at a rate of about 1 million miles each day, it is the fastest spacecraft ever built. Its primary mission is to image the surface of Pluto, its moons, and beyond, and it is now about 90% of the way to its long-awaited flyby in July 2015.