Pluto. Distant, ancient, cold. So very, very cold. A small world with one oversized moon and several tiny ones, occupying an orbit so far from the life-giving Sun that for most of the eighty-six years since its discovery it has existed as only a dim point of light in our telescopes. Even the most powerful of modern earthbound or orbiting instruments can only give hints as to its character, its personality. Pluto; so tiny, so far away, so inconsequential.
And yet…
As I write this the New Horizons probe is homing-in on the “former” ninth planet*. Tomorrow this robotic emissary will fly by Pluto, passing less than eight thousand kilometers from its surface. After a journey of more than nine years a human-made “bullet” will streak past the Plutonian satellites and give us our first (and for quite a long time, last) close-up images of Pluto and Charon.
Frankly, I’m completely psyched!
Pluto has been a source of wonder and an imaginary destination for me since childhood. I can still clearly remember the science fiction stories and popular scientific speculation as to what it would be like, and what we might find when we first made it that far out. In my teens I read the story of Pluto’s discoverer, a Kansas farm-boy named Clyde Tombaugh who went to work at Lowell Observatory in Flagstaff, Arizona; an amateur astronomer who, through perseverance and skill, “made good” and added to our knowledge and understanding of the Sun’s family of planets.**
To date I have orbited the sun fifty-three times; Pluto has accomplished less than one quarter of its “year” in that same period, one of its orbits requiring over two hundred and forty-seven of our years. I’ve observed it several times through the telescope over the years—first when I was only fifteen years-old, and at that age experienced a sense of awe in the viewing entirely out of proportion to the image itself; that dim point of light, indistinguishable from any other except via a careful process of elimination, seemed so much more to me than “just” another star. Growing up in the age of Apollo and Skylab as I was, that impossibly remote mote was to me a goal—a destination. A place to be visited and explored—another world waiting for man’s indomitable curiosity.
And now it’s happening, though not in the way I imagined it.
Fresh from the lunar landings of Apollo, I and my friends were convinced that human landings on Mars lay but a decade or so away, Jupiter perhaps twenty-five years, Saturn just a few more. Our imaginings were of tough, pioneering humans in tremendous spacecraft blazing nuclear-powered trails across the outer Solar System. Naïve? Admittedly, yes; as youngsters we could not see the Space Race as the politically-motivated effort that it was. Nor could we understand the transient nature of the Public’s fascination with space flight; if you had suggested to us in late 1969 that the Apollo program would end after only six successful missions we’d have thought you mad. No, we weren’t living in the real world. We lived in a better place.
While the human exploration of space would remain in Low Earth Orbit for at least the next four decades, another hardy brand of explorer was in the 1960s and ‘70s already blazing those trails that we dreamed of. Our pathfinders in the Solar System would not be mammoth manned spacecraft as imagined but instead compact, affordable space probes. In the shadows of the Mercury and Gemini programs they had already been hard at work on an initial reconnaissance; the Explorers, Lunar Rangers and Orbiters, Luniks and Surveyors were the first wave of the invasion, testing the waters before human life could be committed to deep space.
As Apollo left man’s footprints on the Moon the Mariners and Veneras probed Mars, Mercury and Venus for the first time, and as the Skylab orbiting laboratory and Apollo-Soyuz rendezvous mission were being executed the Pioneer twins, 10 and 11, were aloft on their missions to Jupiter. And there were more robotic explorers; the twin Vikings were the first to land on Mars in 1976, Giotto probed Comet Halley a decade later, and the magnificent Voyagers, initially following in Pioneer’s tracks, made a Grand Tour of the giant planets Jupiter, Saturn, Uranus and Neptune. Pathfinder, NEAR, Curiosity…the list goes on.
And what have we learned from these missions? The photos sent back to Earth fill dozens of coffee-table books, the data returned fill many libraries for eager researchers to explore, but what is the most important thing learned, the vital message sent back from dozens of un-manned spacecraft ranging across the Solar System? What have their sensitive instruments and cameras accomplished for all of us, every human being?
Simple. Each time these mechanical and electronic extensions of our senses have crossed vast distances to reach other planets, dwarf planets and asteroids; each time they’ve lifted the metaphorical veil of yet another unique member of our Sun’s family; each time they have given us (quite in-expensively) a fresh look at what had before been only a fuzzy dot on an observatory photograph or a faint, starlike object moving slowly across my telescope’s field, they have done an amazing, priceless thing in every case.
They have given us worlds. They have changed our perspectives, our viewpoints; taken what were for untold millennia only distant, moving lights in the sky—or even objects invisible to our limited vision—and made them real. Made them not simply abstractions or dimensionless wanderers in the heavens but places. Just as our Moon stopped being simply a bright light in the evening sky forty-six years ago, so do our un-manned probes alter our perceptions of the myriad worlds that surround us.
And now it is Pluto’s turn. In the next few hours Clyde Tombaugh’s discovery of eighty-five years ago will be forever changed in our perceptions, an irreversible alteration in the way we will think of Pluto. Yesterday that tiny world orbiting beyond Neptune was only a faint point of light to me; tomorrow in the wake of New Horizons’ historic flyby it will be a different place. A plant/dwarf planet with geology, weather and unique features, dynamic in its own way.
I can’t wait.
* In 2006 the International Astronomical Union established a definition for “Planet” (interesting that in more than three thousand years of astronomy no-one had done this) which places Pluto—and quite a few other objects traveling the hinterlands of our Solar System—in the category of “Dwarf Planet”. There has been quite a bit of media attention given to this “demotion”, and I’ve been asked many times about it at star parties and whilst volunteering in the Virginia Living Museum
** Tombaugh’s story, I think, is often mis-represented. He is portrayed as the yokel who ‘lucks’ into fame and prominence, which couldn’t be further from the truth. Yes, he lived on a farm, but what made his employment by Lowell Observatory possible were his well-known amateur astronomical accomplishments and skill at designing and fabricating precision telescope optics. Like many amateur astronomers are doing today, Tombaugh’s abilities and observations paved the way to his association with a major astronomical institution; there was no “luck” involved.
I actually met Clyde Tombaugh in March of 1980. As a member of the Flagstaff Astronomical Society and a volunteer at Lowell Observatory I received an invitation to the ceremonies commemorating the fiftieth anniversary of the discovery of Pluto, and you might say that this particular 17-year-old amateur astronomer was ecstatic over the chance to attend such an event. Mr. Tombaugh was 74 years-old then (he would live another 16 years), and I was thrilled not only to have the chance to shake his hand but to have a few minutes to speak with him—and to have him autograph my program for the evening!
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