In which we marvel at just how profound it is that NASA's New Horizons is set to pass the icy dwarf planet.
Given the relatively small size of our planet in terms of cosmic things, our earthling brains can have a hard time grasping really long distances. The almost 25,000 miles around the planet, that makes sense. That the moon, on average, is 238,855 miles away … this isn’t too hard to fathom. But when we start inching our way out into the solar system, it starts to get a bit profound. Take Pluto.
NASA’s New Horizons spacecraft is set to swoop by Pluto this month, which is (on average) 39 Astronomical Units (AU) away. An AU is the distance by which astronomers measure distances; it’s based on the distance between the Earth and our big star, about 93 million miles. Which puts Pluto at a distance of 3.7 billion miles away. Honestly, even a billion is hard to get one’s mind around. Yes, it’s one thousand millions, but what’s that like in more practical concepts? A billion minutes ago, the Roman Empire was going strong. A billion hours ago, the Stone Age was doing its thing.
So, 3.7 billion miles. How can we relate to that kind of mileage? Adam Frank at NPR asked the same question and decided to calculate it in terms that most of us are familiar with: driving.
Using the simplest calculation – a straight line from Earth to Pluto, ignoring the motion of each planet, and driving at a steady 65 miles per hour – he figured it would take … 6,293 years.
“Of course, a 6,293-year-long road trip is not something you want to try with little kids. The asteroid belt is nothing but tourist traps and the rest stops really thin out after Saturn,” Frank writes, so he also gives up the calculation were we to fly by Boeing 777. With a maximum velocity of 590 miles per hour, the trip to Pluto will only take about 680 years.
Which really puts things into perspective when considering just how wild it is that we have a spacecraft about to reach Destination Pluto. Launched in January of 2006, it now travels at more than 50,000 miles per hour. A figure that on its own is even hard to fathom.