When the astronomer Clyde Tombaugh discovered Pluto in 1930, the writer H. P. Lovecraft recognized that this piece of late-breaking news could give one of his far-fetched tales a hint of ripped-from-the-headlines authenticity. He was drafting a story called “The Whisperer in Darkness,” a blend of horror and science fiction that involves lobster-like aliens, human brains encased in metallic cylinders, and “the dark planet Yuggoth, at the rim of the solar system.” (It’s better than it sounds.) Lovecraft was striving to improve the story, and he hit upon the idea of making Yuggoth a stand-in for Pluto. In a letter to a friend, he expressed his excitement about what Tombaugh had spotted in the skies: “I have always wished I could live to see such a thing come to light — & here it is!”
I know how he feels. As a boy, I tracked Voyager 1 as it zoomed by Jupiter and Saturn, and then Voyager 2 as it transmitted stunning images from Saturn, Uranus, and Neptune. They filled my head with wonder, making it a fertile place for the words of authors such as Arthur C. Clarke, Frank Herbert, and Lovecraft, as well as the scenes of Star Wars and its progeny. If I’d been any good at math, I might have become one of those people who now devote their careers to detecting planets that circle distant stars. Or perhaps I would have joined the team behind New Horizons, the NASA probe launched in 2006 and scheduled to reach Pluto on July 14. It promises to send back the first close-up look at a previously unvisited major body in our solar system since 1989, when we saw the majestic blues of Neptune.
Except that our pending encounter with Pluto fills me with a peculiar anxiety. I want to see the pictures of this little world as much as anybody. As we learn what Pluto is, however, we’ll also learn what it’s not, such as the “fabricated metal ball” that Clifford D. Simak imagined in his 1973 short story “Construction Shack.” The astonished explorers of his tale go on to examine Pluto’s smooth surface and uncover a startling secret about life, the universe, and everything, in what could have been the source for a good episode of The Twilight Zone. As Larry Niven wrote in “Wait It Out,” a 1968 story about a troubled mission to Pluto: “A new world would hold infinite surprises.”
Will Pluto? We’ll probably find that it’s just another ball of rock and ice. We’ll collect the cold, hard facts about its geology, atmosphere, and temperature. We’ll debate once more whether it’s really a planet. We’ll gain new knowledge about our solar system. As we do, however, we’ll lose a bit of the here-be-dragons mystery that surrounds terra incognita — and I’m going to miss it.
From the moment of its discovery, Pluto has served as a lodestar of the imagination, inspiring both artists and scientists. Legend has it that Walt Disney chose the name of Mickey Mouse’s dog because he wanted to build on the buzz from Tombaugh’s discovery. The radioactive element plutonium, with its unfortunate symbol “Pu,” also took its name from Pluto, before it went on to become the active ingredient in Fat Man, the atomic bomb that destroyed Nagasaki. (Little Boy, the bomb dropped on Hiroshima, used uranium, also named for a planet.)
The original name, of course, comes from classical mythology: Pluto is the Roman god of the underworld, a dark place where the souls of the dead wander in the afterlife. It’s also a stomping ground for heroes. Descents into it were staples of ancient storytelling, featuring Hercules, Orpheus, Theseus, and others. Their risky journeys serve as worthy models for New Horizons as it hurtles at a speed of more than ten miles per second into the remote reaches of the solar system, where the tiniest glitch could doom its decade-long mission.
Tombaugh’s technology was much more primitive. He found Pluto with the help of a blink comparator, a device that allowed him to see a dot of light change position in a pair of photographs he had taken a few nights apart, from Lowell Observatory in Flagstaff, Ariz. (This is another source of Pluto’s name: Its first two letters match the initials of Percival Lowell, an astronomer who wanted to see life on Mars through a telescope.)
Tombaugh was only 24 at the time of his breakthrough, and for the rest of his life — he lived to 90, dying in 1997 — he watched Pluto’s progressive diminution. At first, scientists thought Pluto was about the size of Earth. As measurements became more precise, it shrank in both size and stature. Today, we know that its mass is about two-tenths of 1 percent of Earth’s, and its surface area is somewhat less than South America’s. It has become the lonely runt of our solar system’s litter, with all of the attendant sympathies. Americans have held it in special regard: Europeans found Uranus and Neptune, but Tombaugh was a farm boy from the Midwest.
Starting in 1992, however, the stargazers began to locate a lot more runts: a herd of Pluto-like objects outside the orbit of Neptune, in a region known as the Kuiper belt. In 2005, they found Eris, which is a touch bigger than Pluto. The next year, the International Astronomical Union voted to downgrade Pluto from being one of just nine full-fledged planets to being one of many “dwarf planets.” Despite my fondness for Pluto, part of me wanted to applaud the new designation: In a world of ever-lowering standards, a group had made the daring choice to reassert them, to howls of protest.
My fascination with Pluto never had much to do with an astronomical classification, but rather with how a speck of light on a photographic plate could open vistas of possibility — or impossibility. E. E. “Doc” Smith, a founding father of the “space opera” genre of science fiction, described Pluto in his 1950 novel First Lensman as the home of an alien colony that has not yet noticed Earth. One of his protégés, Robert A. Heinlein, made Pluto a prison for unruly earthlings in his 1958 young-adult novel Have Space Suit — Will Travel. My favorite piece of Plutonian prose came in 1984, when Kim Stanley Robinson published Icehenge. Its title refers to an enigmatic, megalithic structure, similar to Stonehenge, at Pluto’s north pole. “It had the look of mind marking cosmos, like the paintings on a cave wall,” comments Robinson’s narrator. But what was it doing on Pluto? Now there’s an interesting question, evoking memories of 2001 and its black monolith — and a question that New Horizons and its high-resolution images will kill forever, when they reveal that there’s no such thing.
Perhaps major revelations really do await us. As recently as 1978, astronomers came across a big one when they spied Pluto’s moon, Charon. It’s so large compared with Pluto that the two bodies form a binary system: They revolve around each other, orbiting a point in space. Even so, NASA’s website boasts that New Horizons represents a kind of conclusion, as it “allows the U.S. to complete the reconnaissance of the solar system.”
I’m starting to think of the places we haven’t reconnoitered. Last year, when astronomers announced the existence of 2012 VP113 — a tiny planetoid well beyond the orbit of Pluto — I took to the website of National Review and made a suggestion: “Its name should be Yuggoth, in tribute to the writer H. P. Lovecraft.” I e-mailed the idea to Leslie S. Klinger, editor of The New Annotated Lovecraft. He replied that this wasn’t quite right, because Lovecraft clearly defined Yuggoth as Pluto, rather than as another thing. Then he mentioned an overlooked line from a fevered passage in “The Haunter of the Dark,” the last story Lovecraft ever wrote: “I remember Yuggoth, and more distant Shaggai, and the ultimate void of the black planets.”
It recalled something that the astronomer Gerard P. Kuiper (of Kuiper-belt fame) once said to Clyde Tombaugh: “The finding of Pluto was an important discovery, but what you did not find out there is even more important.” Pluto may come into the clutches of our scientists and engineers, but the rest of us can always dream of Shaggai — a permanently undiscovered country.