Part I of II
Far from the city, where artificial light is dim or absent, the nighttime sky is a perfect wonder. On a clear night it’s an amazing cluster of lights suspended in the most naturally haphazard way. Amazingly, each individual twinkle holds the exact same position, the same wonderment, as when our planet’s first inhabitants gazed skyward.
Since then, our understanding of space has grown exponentially. Still, because of the immensity of the Universe, this ever-increasing knowledge barely fills a teacup. Nevertheless, its infinite sprawl continues to inspire in the same way the unknown inspired early day explorers who looked out and could only wonder what existed beyond the horizon.
In mid-July, the National Aeronautics and Space Administration, NASA, added a bit more to our understanding of space when it flew a probe past the last known planet in our solar system. The New Horizons mission, launched nearly a decade ago, glided past Pluto taking the first finely detailed photographs of its surface. As it did so, it also conducted tests on the planet’s makeup.
“It was kind of a Christmas morning feeling,” said NASA spokesperson Laurie Cantillo, from her Washington, D.C., office. It was also, she said, “the realization of a dream.” In fact, it was a dream hatched and nurtured, in part, by a Coloradan and a former Coloradan.
The dream came together in fits and starts. Initially imagined by scientists Alan Stern, a University of Colorado graduate, and the University of Colorado’s Fran Bagenal in1989, the idea of a mission to Pluto failed to impress. After some budget refinements, a more focused mission statement, configuration issues solved and, of course, competing scientific interests addressed, NASA gave its blessing.
January 19, 2006, New Horizons launched. At a speed of just more than 39,000 miles per hour, it zipped past the moon in mere hours. It crossed the Martian orbit five months later, all the while sending back data on what it observed. But for the remainder of its trek it transmitted data only on a periodic basis. To save fuel, the spacecraft would, from time to time, be ordered into hibernation. But last December NASA woke it up to complete the mission.
On July 14, 2015, New Horizons radioed back – from a distance of 2.97 billion miles – what scientists Stern and Bagenal had imagined when they had their initial conversation about Pluto some 3,363 days earlier. But this time, they had pictures to go with it.
“They had one shot,” said NASA’s Cantillo, “and they nailed it.” An understatement, actually. The mission’s success, was much more than a flyby. It was, say scientists, more like firing an arrow into the darkness from New York and hitting the bulls-eye in San Francisco.
For Professor Bagenal, who teaches astrophysics and planetary sciences at CU and who speaks with a modesty that masks the enormity of the mission, New Horizons’ success was just good science. “It was the obvious place to go,” she said in a business-like tone during a recent phone conversation.
Bagenal said the mission’s success confirmed a number of theories science previously held about PIuto. But, in addition to turning theory into hard evidence, there was also plenty of new ground broken on the mission. “We found a lot of surprising things,” including data on the planet’s geology, its surface, its atmosphere and its largest moon, Charon.
The mission also finally determined a precise measurement for Pluto. Until New Horizons, science was only guessing about the planet’s size. Scientists now know Pluto’s land mass is approximately twice the size of Texas. “There are many questions remaining, lots of stuff to work on. But you answer your questions and you keep looking,” said Bagenal.
Capturing images on this distant planet is no small feat. To do so required the creation of brand new technology. That is where another Colorado connection to New Horizons enters the picture.
The camera photographing Pluto was developed by Colorado’s Ball Aerospace. Its clarity is amazing, says Mission commander Stern who wrote about New Horizons for TIME Magazine. Photographed from a distance of approximately 6,000 miles from the surface, the pictures show remarkable detail. How remarkable? Imagine pointing a camera in New York across the Atlantic and getting back images showing an in-focus Eiffel Tower.
Despite the bonanza of receiving data unimaginable just a few years ago, there is a natural frustration to what scientists are receiving. Because Pluto is so far away, images sent back today are not immediately retrievable. In fact, scientists will have to wait another sixteen months before all of New Horizon’s cache of information will be in their hands.
But what they’ve received to date, is scientifically tantalizing. The latest images show topography that resembles dunes, a feature no one ever imagined would be there.
When discussing the mission’s success, it’s important to note that it was achieved using ‘ancient’ technology, that is, equipment that would be considered outdated in any modern laboratory environment. Put another way, New Horizons is traveling with the equivalent of a ten-year-old computer, essentially, an antique.
But, while old technology is a drawback, it’s just the way it goes, said Bagenal. “The reality is you’re not going to put the best technology (on board).” Something reliable, she said, is far more important than the latest widget. “Rather than the fancy car that might break down, you go with a reliable old Ford that will go and go and go.”
The capabilities and limitations of New Horizon’s payload will be tested over the next decade. That’s because mapping Pluto is only part of the mission. The remainder, before New Horizons is shut down sometime in 2026, will be an exploration of the Kuiper Belt, the region that separates our solar system from interstellar space.
Taking readings of the Kuiper Belt will depend mightily on the Student Dust Counter, an instrument built by CU-Boulder undergraduate and graduate students in the Laboratory for Atmospheric and Space Physics. Its job is to detect and analyze interplanetary dust, a component of the mission that will seriously expand our knowledge of this previously unchartered territory.
The SDC, also the only student-built instrument ever flown on a planetary mission, will remain busy for the next decade. The Kuiper Belt, a region estimated to stretch more than a billion miles across, is home to an estimated 70,000 objects 60 miles in diameter, essentially rocks that would fit neatly into the space that separates Denver from Colorado Springs. Each object contains what science believes is evidence that will help explain how our solar system came into existence nearly five billion years ago.
Short of a mind-boggling discovery, much of what New Horizons detects over the next decade will be information that only science can appreciate. But, the information gathered from its fly-by also means the construction of one more rung on the ladder that will one day allow man to climb higher into the heavens and learn more about his place in the Universe.
(Note: In 2006, Pluto was downsized as a planet and reclassified as a ‘dwarf planet.’ However, New Horizons scientists refer to it as a planet. As such, it is referred to as a full planet in this story.)