Category Dreams of Other Worlds

Observations of the cosmic microwave background rapidly im­proved, and it was soon found that the radiation had a spectrum almost perfectly consistent with one temperature, a type of radia­tion with what is called a thermal spectrum. This was additional support for its interpretation as relic radiation, because such a smooth spectrum only results from radiation that’s in equilib­rium with its surroundings. Since in this case the surroundings are the universe itself, thermal radiation is expected. Its temperature is 2.725 K and it is the most accurately measured temperature in nature.23

By the early 1970s, theorists had predicted that the microwave radiation should not be perfectly smooth. That’s because a slightly uneven distribution of matter causes very small variations in tem­perature, with denser regions hotter. The subtle variations in den­sity act as the seeds for later structure formation. Theories of gal­axy formation could not generate large lumps of matter without a little lumpiness with which to start. The initial variations are not really like “lumps” since they are physically extremely large and extremely shallow. In a purely metaphorical sense, the mighty oak trees that are present-day galaxies grew from the tiny acorns of anisotropy in the background radiation.

NASA’s Cosmic Background Explorer (COBE) was launched in 1989 to make more precise measurements of the microwave radia­tion than could be made from the ground or from high altitude bal­loons. COBE was cheap by modern standards, about $150 million, and extraordinarily successful. It confirmed the exquisite thermal nature of the spectrum, ruling out the last few remaining potential explanations other than a big bang. With only four years of data, the satellite was able to detect minute variations from smoothness; the radiation deviated from a constant temperature from one part of the sky to another by one part in a hundred thousand.24 These were the long-sought seeds of structure formation. Commentators and media pundits breathlessly embraced the story when project leader George Smoot talked about having discovered the “finger­prints of God.”25 Smoot and his colleague John Mather shared the 2006 Nobel Prize in Physics for their heroic work in advancing cosmology with the detection of these tiny fluctuations.

But there’s an extraordinary twist to this story. The smooth­ness of the microwaves and their perfectly thermal spectrum are difficult to explain in the standard big bang model because the universe was expanding so quickly early on. At the time the micro­waves were released, two points in space were receding at nearly sixty times the speed of light. Under these conditions, there’s no way disparate parts of the universe could come into equilibrium so adjacent patches of the sky shouldn’t be at exactly the same tem – perature.26 A related puzzle is the near-flatness of space. General relativity is based on curved space-time and it was expected that the vast mass of the universe would give an imprint of curvature. The cosmic background microwaves have traveled across the en­tire universe so should reveal if the space they’ve traveled through is curved. It’s not. To explain the smoothness of the radiation and the flatness of space, cosmologists have hypothesized a fantasti­cally early time, only 10-35 seconds after the big bang, when the en­tire universe expanded exponentially due to physics involved with the unification of three fundamental forces of nature. This event is called inflation.

Inflation modifies the big bang theory by positing that all we can see to the limit of vision of our telescopes—called the observ­able universe—is a small bubble of space-time that inflated to be­come large, smooth, and flat. The totality of space-t ime is very much larger, perhaps infinitely larger. Moreover, the variations in radiation that will grow to become galaxies are quantum fluctua­tions from a tiny fraction of a second after the big bang.27 It’s an extraordinary hypothesis.

Even to the naked eye, Mars clearly varies in brightness over months and years. Mars is roughly 50 percent farther away from the Sun than the Earth, and its distance from us depends on which side of the Sun each planet is on and the details of their elliptical orbits. At its closest,9 Mars is only 55 million kilometers away and, at its farthest, it’s 400 million kilometers away. This variation cor­responds to a factor of 50 in apparent brightness and a factor of 7 in angular size. Only the brightness variation is visible to the naked eye; a telescope is needed to resolve Mars into a pale red disk. Even when it looms closest in the sky, Mars is just 25 arc seconds across, or seventy times smaller than the full Moon.

Following the invention of the telescope, the view of Mars evolved relatively slowly. Galileo began observing Mars in Septem­ber 1610.10 He noticed that it changed in angular size and he specu­lated that the planet had phases. The Dutch astronomer Christian Huygens was first to draw a sketch with surface features, in partic­ular the dark area or “mare” called Syrtis Major. Huygens thought Mars might be inhabited, perhaps by intelligent creatures. In the middle of the seventeenth century, Giovanni Cassini and Huygens first spotted the pale polar caps of Mars,11 and in the early eigh­teenth century Cassini’s nephew Giacomo Maraldi saw variations in the polar caps that he speculated were due to water freezing and melting during the Martian seasons, although he could not rule out varying clouds.12 William Herschel used his state-of-the-art tele­scopes for a period of more than eight years beginning in 1777 to bolster the interpretation that the poles were made of frozen water. He had measured the tilt of Mars’s spin axis relative to the plane of its orbit so knew it had similar seasons to the Earth. He had also read Huygens’s posthumous book Cosmotheoros in which the Dutchman speculated about life in the Solar System. In an address to the Royal Society in London, Herschel asserted boldly: “These alterations we can hardly ascribe to any other cause than the vari­able disposition of clouds and vapors floating in the atmosphere of the planet. . . . Mars has a considerable but modest atmosphere, so that its inhabitants probably enjoy a situation in many respects similar to our own.”13 With respected scientists setting up the ex­pectation of life on Mars so long ago, it’s not surprising that the idea had taken deep root by the modern age.

Telescope design continued to improve through the nineteenth century, allowing telescopes to make sharper images and resolve smaller features on Mars. In 1863, the Jesuit astronomer Angelo Secchi saw the maria appear to change in color; he fancifully drew them as green, yellow, blue, and brown at different times. He also saw two dark, linear features that he referred to as canali, which is Italian for grooves or channels.14 It was a fateful choice of words, because the literal English translation as canals suggests construc­tion by a technological civilization.

Behind every successful robot rover there’s a driver. Actually, four­teen drivers in the case of Spirit and Opportunity. For those peo­ple used to the gray, male gristle of the typical scene at Mission Control in Houston, the rover drivers are surprisingly young, and many are women. Drivers don’t control the rovers in real time with a joystick; the reasons are that real-time control would be far too hazardous, and there’s no immediate feedback. Depending on where the Earth and Mars are in their orbits, the distance can vary from 35 to 200 million miles, and the time delay for a signal can be as high as twenty minutes.

The drivers are part of a much larger team of engineers and scientists, numbering over two hundred, who are all involved at some level in what the rovers do. On a typical day, the results of the previous day—which are part of a larger strategy involving weeks or months of roving—are evaluated as quickly as possible, usually within an hour. Then the drivers work with the science team to map out the day’s activities, which might involve measure­ments of an interesting rock or navigating around obstacles. This is turned into a set of commands that the rovers can execute. Com­mands are turned into a realistic animation and reviewed with the science team. Then they are picked apart for anything that could go wrong. All possible contingencies are considered. The final list of commands is reviewed twice and sent to the rovers to execute. Then the process starts again, as it has for over 2,500 days. The only break comes during each Martian winter when the rovers hibernate and conserve power.

There’s a catch. A Martian day is 40 minutes longer than a Ter – ran day. So each day drivers begin their days 40 minutes later than the day before. As driver Scott Maxwell has said, “Pretty soon, you’re starting your day at midnight, at 2 a. m., at 4 a. m. (figure 3.4). It’s been called ‘Martian jet lag’—it’s tough on bodies, on brains, on relationships.”31 It leads to fatigue, which leads to mis­takes. So many drivers watch their caffeine intake and keep to Mars time even on their days off, which puts further strain on relationships and adds to the “otherworldliness” of the job. As for what it feels like to control a robotic vehicle on another planet, listen to Ashley Stroupe, one of the most experienced drivers: “It’s really just awe inspiring. Probably the closest I’ll ever get to being an astronaut. Going to new places and being the first human eyes to see them is profound and hard to describe. It’s the best job I could imagine.”32

The different personalities of the rovers project into the driving experience, as Stroupe explains: “The rovers do behave differently!

Spirit and Opportunity are first in very different terrains, and so you have to drive them differently. Also, they have aged differently and have driven us to use very different strategies. We have to drive Spirit mostly backward to drag the broken right front wheel, and we have to drive Opportunity with the robotic arm out in front since one of the joints broke and we can’t stow it anymore.” There are also light moments, as Maxwell describes in his online blog: “Early in the mission, we nearly lost Spirit due to a problem with its flash file system. When we’d diagnosed and fixed the problem, cleaned up the flash drive, and knew that the danger was past, someone wrote this on one of our white boards: Spirit was willing, but the flash was weak.” His greatest driving challenge was trying to get Spirit to a safe haven for the winter by driving across a dune with a balky wheel. As he said, “Imagine trying to cross a desert pushing a shopping cart with one stuck wheel.”

All human cultures communicate by signaling greetings, which serve as an opening that usually indicates a lack of hostility. Whether a presidential address, evening news program, a letter, telephone message, or a friend or stranger’s passing acknowledg­ment on the street, we anticipate salutations.48 Greetings also are an opening to what the ancient Greeks called xenia, hospitality to the unknown other. Biocultural theorist Brian Boyd contends that among ancient Greek cultures, the extension of hospitality, or xenia, initiated collaboration among strangers in a hostile time and region. Particularly in the Iliad and Odyssey texts, hospitality, asserts Boyd, is a core value:

The word xenos, stranger-guest-host-friend, tells a whole exemplary tale in a single word. When a stranger arrives at my doorstep, I am obligated to welcome and feed him. . . even before asking him who he is. . . . The stranger becomes my guest, and to signify that he has therefore also become my friend, I should bestow on him a valuable gift at his departure, and help him on his onward journey. He is then obliged, should I arrive on his threshold, to become my host. . . . But more than that: the bond of xenia created by the initial act of welcome and cemented by the gift should endure between us for life and be­tween our descendants.49

As an example of this, Boyd mentions a scene from the Iliad in which a Greek and a Trojan warrior refuse to fight as their rela­tives were xenoi.

From its inception, Voyager’s Record was understood to be as much a message to ourselves as it was to those who may encoun­ter it. Included are greetings from President Jimmy Carter, who wrote: “This is a present from a small distant world, a token of our sounds, our science, our images, our music, our thoughts and our feelings. We are attempting to survive our time so we may live into yours. We hope someday, having solved the problems we face, to join a community of galactic civilizations.”50 Even as Voyager ex­tends hospitality to possible galactic civilizations, Carl Sagan often reiterated that we must extend to neighboring nations, those we know quite well, an equal largess if we wish to survive millions of years hence. That was the point of Sagan’s talk given in 1988 on the 125 th commemoration of the Battle of Gettysburg:

Today there is an urgent, practical necessity to work together on arms control, on the world economy, on the global environment. It is clear that the nations of the world now can only rise and fall together. . . . The real triumph of Gettysburg was not, I think, in 1863, but in 1913, when the surviving veterans, the remnants of the adversary forces, the Blue and the Gray, met in celebration and solemn memorial. It had been the war that set brother against brother, and when the time came to remember, on the 50th anniversary of the battle, the survivors fell, sobbing, into one another’s arms. They could not help themselves.51

Though seemingly ill-equipped for their mission, Voyager carries from a tiny blue dot of a planet into the unfathomable abyss a gift, a small repository of human artifacts, music, and greetings offering not just xenia but charity that neither expects nor re­quires reciprocity. That was the attribute that ensured our survival as a species and likewise has informed our dream of becoming members of an advanced galactic community. “In their explor­atory intent,” wrote Sagan, “in the lofty ambition of their objec­tives, in their utter lack of intent to do harm, and in the brilliance of their design and performance, these robots speak eloquently for us.”52

Aerogel was created in 1931 as the result of a bet. Steven Kistler wagered a colleague that he could replace the liquid inside a jam jar without producing any shrinkage. In other words, he thought he could fill the volume with something that had the same struc­tural properties but was completely dry. The material that won the bet was 99.8 percent air and has the lowest density of any known solid. Aerogel is made by extracting the liquid from a gel by super­critical drying. This allows the liquid to be slowly drawn off with­out the solid matrix of the gel collapsing under its capillary action, as would occur during evaporation. The first aerogels were made of silica; more recent ingredients include alumina and carbon.11

If you touch an aerogel, it feels like Styrofoam or the green foam that flowers are often pressed into. Pressing on it softly doesn’t leave a mark and pressing on it firmly leaves a slight depression. But pressing down sharply enough will cause a catastrophic break­down of the dendritic structure, making it shatter like glass. It’s light and strong, supporting four thousand times its own weight. Aerogel is a thousand times less dense than glass, and the myriad tiny cells of air trapped inside the material make it one of the best insulators known. Engineers at NASA’s Jet Propulsion Lab learned how to make extremely pure aerogel and it was used as an insula­tor on the Mars Pathfinder mission. Peter Tsou is the wizard at JPL who fabricates aerogels; because of the importance of his skills, he was named deputy principal investigator on Stardust.

With Stardust, the challenge was to capture small particles mov­ing at six times the speed of a rifle bullet without vaporizing them or altering them chemically. Aerogel is perfect for this job; the rigid foam that’s not much denser than air slows the particles down and brings them to a relatively gentle halt, each one leaving a carrot­shaped wake two hundred times its size. Imagine firing bullets into a swimming pool filled with Jello. Stardust’s aerogel was fitted into a module the size and shape of a tennis racket that swung out when the spacecraft approached the comet. One side was turned to face Wild 2, and the other side was turned to face interstellar dust encountered on the journey. Before and after use, the module was stored in its protective Sample Return Capsule (plate 9).12

Stardust flew within 150 miles of the comet on January 2, 2004 and headed back to Earth with its precious cargo trapped like tiny flies in a silica spider web. On January 15, 2006, Stardust returned home after seven years and nearly 3 billion miles of traveling. First, the mission controllers did a short rocket burn to divert the space­craft from hitting the Earth, leaving it with just 20 kg of fuel. Then they fired two cable-cutters and three retention bolts to release the 46-kg return capsule and watched as springs on the spacecraft pushed the capsule away. The capsule streaked into the pre-dawn California sky at 29,000 mph, faster than any man-made object had ever been returned to Earth. The heat shield and parachutes worked flawlessly and the capsule landed in the Utah desert at 5:10 a. m. The few people up and outside that morning saw a fire­ball and heard a sonic boom.

Within two days, the package containing the aerogel was opened in a clean room at the Johnson Space Center in Houston. Stardust was subject to the maximum contamination restrictions, since it returned material from an extraterrestrial object with the potential to host life. In practice, the risk of “infecting” the Earth with alien life was low, since any known organism would almost certainly be destroyed by the high impact speeds in the aerogel, but NASA took no chances. The mission was carried out under a Category 5 plane­tary protection policy, which is even more stringent than Biosafety Level 4, the protocol used to deal with hemorrhagic fevers like Ebola and Marburg.13 That means sterilization by heat, chemicals, and radiation before the spacecraft is launched, and a requirement that the returned samples are handled in a secure facility and never come into direct contact with humans.

Members of the team opened the sample return package in a clean room just down the hall from where hundreds of kilos of Moon rocks are kept, brought back by the Apollo astronauts.14 The room was a hundred times cleaner than a hospital operating theater. They were delighted to see the aerogel segments littered with particle tracks, looking like burrows left behind by micro­scopic creatures. The mission had clearly been a success.

Talan Memmott’s Lexia to Perplexia is an online fictional hyper­text project that interleaves conventional writing with program­ming code for Html and Javascript to explore the ways human culture has been shaped by emerging digital communication tech­nologies. Memmott writes: “The Earth’s own active crust we are, building, building—up and out—antennae, towers to tele*.”55 Memmott evokes an interesting concept. Humans have produced an electronic crust, or an information and technology layer, over Earth’s surface and extending into orbit. This layer of electron­ics is comprised of technologies ranging from radio and televi­sion relay stations perched on mountain tops to fiber-optic lines in homes and businesses, from cell towers dotting the high ground to transoceanic cables in the ocean depths. This data-rich envelope extends from backyard satellite dishes to powerful astronomical radio telescopes lined across the desert in Socorro, New Mexico, to billions of dollars in satellite hardware in low Earth orbit.

This infrastructure transmits information to cell phones, radios, televisions, computers, global positioning devices, emergency ser­vice centers, hospitals, and weather reporting stations, etc. Mem – mott writes, “I spread out—pan—s end out signals, smoke and otherwise, waiting for Echo.”56 The point is that since the ancient past, humans have extended their communication capabilities over larger and larger distances, through technologies that today trans­mit information around the globe at the speed of light. But this diaphanous “skin” is sensitive to the conditions of the space envi­ronment just as our skin is sensitive to the Sun. Never before have we been so dependent upon an understanding of the inner work­ings of the Sun and its impact on the electronics that sustain our information-based culture. As we continue to expand and rely on

this electronic, information layer encasing the Earth, we’re increas­ingly impacted by the Sun’s powerful magnetic reach.

Evolutionarily, we’ve adapted to living with our star. As John Freeman points out, humans, like other mammals, insects, and plants, have evolved “sense organs that can make use of the Sun’s outward flood of electromagnetic radiation. It’s not an accident that our eyes are sensitive to the same portion of the electromag­netic spectrum where solar radiation is most intense.”57 Similarly, our skin is well adapted to sunlight in a number of ways, one being that in about fifteen minutes of exposure our skin absorbs the daily recommended amount of vitamin D. Our lives are intimately bound up with the Sun, and not just because of our need for its light and warmth. The iron in our blood was forged inside massive stars over 4.5 billion years ago and then surfed the blast waves of supernovae into interstellar space. Stars like the Sun spewed heavier elements into space that eventually coalesced into our Sun and Solar System. Harlow Shapley popularized this concept in the early 1900s by claiming that we are made of “star stuff.” The human body, as all life on Earth, is comprised of carbon, calcium, oxygen, and other heavy elements forged in the cores of stars that exploded long before our Sun was born. Given how much more there is to it than meets the eye, it’s fitting that one of NASA’s ini­tial Braille books for the blind focused on the Sun.58

The Solar Dynamics Observatory, launched in early 2010, is carrying on SOHO’s work with even greater accuracy in exam­ining the Sun’s interior and interpreting the sound waves travel­ing inside and across its surface. Part of NASA’s “Living with a Star” program, SDO is tracking magnetic fields within the Sun in hopes of discovering the mechanism that drives the Sun’s eleven – year cycle. SDO is sending data to Earth at a rate a thousand times faster than SOHO, equivalent to downloading 300,000 songs a day. The satellite is 50 percent heavier than SOHO and views the Sun in high definition, or nearly IMAX quality, taking a picture in eight different colors every ten seconds.59 It’s serving as a first alert against magnetic storms sweeping over our fragile home in space.

We’ve learned from SOHO and other missions that the rock­steady light from the Sun, varying by less than a percent from year to year or decade to decade, is not the whole story. In invisible forms of radiation, the Sun is epic and Byzantine in its behavior, and scientists have not fully understood this apparently simple, middle-aged and middle-weight star. Scattered through the Milky Way galaxy, there are an estimated hundred million habitable Earth-l ike worlds orbiting Sun-l ike stars, and each will have its own complex relationship with its parent star.60 Our Sun and the space weather it produces will determine the future of our species as well as that of all life on Earth, even the planet itself. Having sustained our world for billions of years, the Sun is still a devoted protector and guardian. It reaches out across a hundred million miles to cradle, caress, stroke, and occasionally, scold us.

Our vision of distant worlds has improved immensely since Gali­leo first pointed his slender spyglass at the night sky. Observational astronomy has moved from naked-eye observing to the use of large-format CCDs. These devices register an image by converting incoming light first into electrons and then into an electrical cur­rent, and astronomers typically gather light for several minutes up to an hour before reading out the device and inspecting the image. The CCDs that astronomers use are just larger format versions of the ubiquitous detectors found in digital cameras and cell phones. However, before photography matured, the only detector in as­tronomy was the unaided eye, and the only way to record an image was to sketch it on paper. Professional and amateur astronomers are familiar with “seeing,” the rapid fluctuation of images caused by convective motions in the atmosphere; it’s the phenomenon that causes stars to “twinkle.” Viewed through a telescope, star images flicker and dance. But there are moments of stillness when the im­ages become crisp.15 Observers ever since the time of Galileo have learned to swiftly record the view when the seeing is at its best. In those moments when the light is not quite as scrambled by the atmosphere, features become apparent that are otherwise invisible and images seem to snap into focus.

In 1877, Mars was at its closest approach to the Earth, and Giovanni Schiaparelli was prepared to make the best observations of Mars yet. Already a talented observer, he used his skills as a draughtsman to make rapid sketches of the planet during the mo­ments of sharp viewing, and he built up the stamina needed to concentrate intensely in short bursts through a long winter’s night. He made detailed maps, naming features as “seas,” not because he thought they actually contained water, but by tradition, as had been done with lunar features since the time of Galileo. He saw linear features stretching for hundreds of miles across the surface that were evocative of artificial constructions, although he resisted drawing this conclusion (figure 2.1).16 Meanwhile, a separate de­bate raged over whether the atmosphere of Mars contained a sig­nificant amount of water vapor. Some observers claimed that it did, but it’s very difficult to separate the signature of water around a remote planet from the very much stronger signature of water imprinted on the light by the Earth’s atmosphere, and these obser­vations turned out to be flawed.17 As an Italian, Schiaparelli used the term canali, which was once again given an erroneous and literal translation in English-speaking media.

Mars fever began to take hold. The Suez Canal had opened in 1869, so the public was primed to appreciate the engineering achievement implied by canals on Mars. Not every observer could confirm the linear markings, but many of them deferred to Schia­parelli’s skill and assumed that their own shortcomings were the obstacle. Amateur astronomer and author William Sheehan has noted the power of this type of thinking, where expectation and projection can shape the sensory experience: “Schiaparelli had taught observers how to see the planet, and eventually it was im­possible to see it any other way. Expectation created illusion.”18

The scene then shifted to northern Arizona. It was 1894, and Percival Lowell was driving his workers hard. He was racing to build a telescope before a particularly close approach of Mars. The patrician Bostonian had left his gilded life to fuel a personal obsession in the thin air of the northern Arizona desert. The previ­ous Christmas, Lowell had been given a copy of The Planet Mars by Camille Flammarion as a present—Flammarion was a noted French astronomer and popularizer of science, considered by many the early predecessor of Carl Sagan. Flammarion accepted the in­terpretation that Martian canals represented intelligent life and in his book wrote: “The actual conditions on Mars are such that it would be wrong to deny that it could be inhabited by human spe­cies whose intelligence and methods of action could be far superior to our own. Neither can we deny that they could have straightened the original rivers and built up a system of canals with the idea of producing a planet-wide circulation system.”19 Lowell had a prior

interest in astronomy and he correctly judged that the best place to see sharp images was in the high and dry desert air, far from any city lights. The Lowell family motto was “seize your opportu­nity” and Percival took it to heart, dropping his plans of leisurely travel in Asia to venture into the rugged terrain south of the Grand Canyon.

For fifteen years, Lowell studied Mars diligently and produced a series of drawings of intricate surface markings as he perceived them. To Lowell, the canals were real and they were manifestly artificial. Around his observations he wove a story of a dying race, more intelligent than humans, who had built a network of canals to carry water from the poles to the arid equatorial regions.20 Pro­fessional astronomers were skeptical of the observations and their interpretation, and were generally dismissive of the back story, but Lowell bypassed them with popular books and extensive lectur­ing. Lowell published his first book on the subject in 1896, titled simply Mars. Two years later, H. G. Wells incorporated major ele­ments of Lowell’s view of Mars into The War of the Worlds, which was very popular and struck a nerve with the public. The War of the Worlds was first published in magazine serial form, in the tradition of the novels of Charles Dickens. As a book, it has never been out of print and has so far spawned five movies, a TV series, and numerous imitators. At this point, cultural and scientific views of Mars were closely twined.

Lowell’s 1906 book Mars and Its Canals met with a strong re­buttal from Alfred Russel Wallace, co-discoverer of the theory of natural selection, who argued that Mars was far too cold to host liquid water. He considered that the polar caps were made of fro­zen carbon dioxide, not water ice, and he concluded that Mars was uninhabited and uninhabitable. Wallace’s critique made no differ­ence in the cultural arena. Ten years later, Edgar Rice Burroughs published A Princess of Mars, set on a version of the red planet alive with exotic animals, fierce warriors, and princesses in near­human form. He wrote another ten Mars stories over the follow­ing thirty years, inspiring Arthur C. Clarke and Ray Bradbury and launching a grand tradition of Mars science fiction.21

Mars fever was resistant to the medicine of improved astronom­ical observations.22 Lowell stubbornly defended his position until the end of his life, saying in 1916: “Since the theory of intelligent life on the planet was first enunciated twenty-one years ago, every new fact discovered has been found to be accordant with it. Not a single thing has been detected which it does not explain. This is re­ally a remarkable record for a theory. It has, of course, met the fate of any new idea, which has both the fortune and the misfortune to be ahead of the times and has risen above it. New facts have but buttressed the old, while every year adds to the number of those who have seen the evidence for themselves.”23 By 1938, telescopic remote sensing had demonstrated beyond any reasonable doubt that Mars was a dry, barren, lifeless desert, but that didn’t dim the twinkle in Orson Welles’s eye as he reeled the public in with his artful hoax.

The fever cooled dramatically in 1965 with Mariner 4. Spurred into existence by a series of firsts for the Soviets in space, NASA was a young government agency with ambitious plans. By the mid – 1960s the hardware development for the Apollo program was in full swing, but NASA also wanted to gain the initiative in inter­planetary probes.24 The Mariner series of space probes was de­signed to investigate the inner Solar System. Space exploration was definitely not for the faint of heart; in the 1960s roughly half of NASA’s probes failed. Mariners 1 and 2 were intended for Venus. Mariner 1 veered off-course and had to be destroyed just after launch, while Mariner 2 made it to Venus and transmitted useful data as it flew by. Venus was known to have thick, opaque clouds so there was no camera on board. Mariners 3 and 4 were intended for Mars. Mariner 3 mysteriously lost power eight hours after launch, so all eyes turned to Mariner 4.25 After seven months and 220 million kilometers of travel and one mid-course correction, it swooped within 10,000 kilometers of the planet’s surface.

The spacecraft sent back twenty-one black and white images, the first pictures ever taken of a world beyond the Moon by a space probe. The images were small and grainy, with eight times worse resolution and sixty times fewer pixels than a typical cell phone camera. They showed a barren and cratered surface. Other instruments indicated a sparse atmosphere, daytime high tempera­tures of -100°C, and no magnetic field that would be needed to protect the planet from harmful cosmic rays.26 Mars, so deeply rooted in the popular consciousness as a living world, seemed to be Moon-like and lifeless.

Many of the rover drivers are younger than thirty-five years old. In general, planetary science is an older man’s game; it takes more than a decade to plan and execute a space mission, and the pro­portion of women in the profession has been growing, but from a low base. However, NASA understands that the vitality of the space program depends on inspiring young people and broad­ening the participation of women. The Mars Exploration Rov­ers have set a strong example of engaging the next generation. It started with a third grader naming the rovers, as we saw in the opening vignette.

The trail was blazed by nine kids aged from ten to sixteen from around the world who won an even earlier essay contest. Their prize was to have guided a robotic rover on the Mars Surveyor mission, but that mission was cancelled. In March 2001, they came to the United States to work with the Mars Global Surveyor or – biter, where they became the first members of the public to ever command a NASA mission. The next set of eight students was selected from thousands of applicants who had to write a journal saying how they would use a rover to explore a hypothetical site on Mars. Aged eleven to seventeen, they came to JPL in Pasadena in 2002 to simulate two days of exploring Mars with a prototype of an advanced rover called Fido. They experienced the same train­ing given to mission team scientists.

All this led to the selection of sixteen “Student Astronauts” from another international essay contest, sponsored by the Planetary Society. The eight boys and eight girls, ages thirteen to seventeen, came to JPL in early 2004 and were the first group of kids ever to participate in the daily operations of an ongoing Mars mis­sion. They were in the thick of things as Spirit and Opportunity made some of their most interesting discoveries. Snippets from the children’s online diaries give a sense of their experience. Courtney Dressing from the United States said, “Today was definitely the best day of my life! Spirit landed on Mars!” Saatvik Agarwal from India said, “It’s really amazing how scientists just stop with what­ever they are doing and explain it to us without feeling irritated!” Kristyn Rodzinyak from Canada commented, “Today has been a very exciting sol! I can’t wait to start working on new images for these sols and on the other rover!” Camillia Zedan from Great Britain: “The overall message from all meetings is one of enthu­siasm; just keep on truckin’. I must admit that I still can’t believe that I’m actually here.”33

A follow-up of these young people five years after the rovers landed showed that almost all of them are pursuing science degrees and heading for careers in science or the aerospace industry. Their passion for space is undiminished. Their dreams of other worlds were nurtured profoundly. They of course were lucky enough to have a singular experience, but the Mars rovers have also reached into the lives of a much larger number of people.

Voyager’s interstellar mission summons up the voice-over at the beginning of what began as a seemingly minor television series, initially aired between 1966 and 1969, titled Star Trek: “to boldly go where no man has gone before.” Those words, immortalized by William Shatner in his role as Captain James T. Kirk of the starship Enterprise, have powerfully shaped popular discourse regarding space exploration. By the late 1960s, Americans were tuning their televisions to watch the space drama created by Gene Roddenberry and developed along with Herb Solow, Gene Coon, Matt Jeffries, and Bob Justman. The impact of Star Trek has been unprecedented and unparalleled. In decades of syndication, the se­ries would inspire and captivate a global audience. Film historian Constance Penley points out that in the cultural discourse Star Trek became inextricably linked with NASA. Describing the con­flation of NASA and the television series in its various iterations as a “powerful cultural icon,” Penley contends that “NASA/TREK shapes our popular and institutional imaginings about space ex­ploration.” By 1976, NASA and Star Trek were so intertwined in the popular thinking that, at the request of Star Trek fans, Presi­dent Gerald Ford was persuaded to change the name of the newly unveiled prototype space shuttle from Constitution to Enterprise. Penley writes, “Many of the show’s cast members were there as the Enterprise. . . was rolled out onto the tarmac at the Edwards Air Force Base to the stirring sounds of Alexander Courage’s theme from Star Trek.”53 Then JPL Director Bruce Murray recalls that a year later, in 1977 when the Voyager spacecraft were launched, funding for the planned Jupiter Orbiter with Probe (JOP) project had been cancelled. That summer, Gene Roddenberry happened to be speaking at a Star Trek convention in Philadelphia and encour­aged the five thousand attendees to contact their congressional representatives to save the mission.54 Whatever the reason was for the reversal, the Jupiter mission eventually was supported as the Galileo Orbiter.

That Star Trek touched a powerful chord in the public sphere is unquestioned. William Shatner has observed that the original Star Trek series went on to become the most successful television series ever produced, and has evolved into a huge industry comprising spun-off TV series, motion pictures including J. J. Abrams’s Star Trek (2009) and Star Trek Into Darkness (2013), as well as novels, cartoons, action figures, Trek conventions, and many marketing products.55 By aligning the space agency with the Star Trek fran­chise, NASA has realized even greater public interest. In 2011, the Kennedy Space Center (KSC) attracted visitors with “Summer of Sci Fi: Where Science Fiction Meets Science Fact.” The event was designed to combine “the technology, innovation and exploration of NASA with the adventures of Star Trek.” Its website featured a retro image of Spock, modeled on the 1960s series, with his hand raised in the Vulcan greeting of “Live long and prosper.”56 Activi­ties included a live theater production that posed the audience as new recruits for Starfleet Command, a shuttlecraft simulator, “Star Trek: The Exhibition,” and an opportunity to win a suborbital flight with XCOR Aerospace, whose Lynx aircraft is to be piloted by former astronaut Rick Searfoss.

The Voyager mission was even featured as a plot device in Star Trek: The Motion Picture (1979) when Kirk reunites with his for­mer crew to save the Earth from a sentient spacecraft that eradicates everything in its path as it searches for its creator. Unfortunately for Kirk and his crew, the entity views them as a carbon-based infestation of starships. It gains sentience after unknown aliens re­pair the old Earth spacecraft that forms its core, the name of which is V’Ger, a corruption of the word Voyager and likely derived from the acronyms given the Voyager spacecraft. A test model of Voy­ager was labeled VGR77-1, while the spacecraft actually launched were titled VGR77-2 and VGR77-3.57 On a recent NPR Science Friday program, Ira Flatow asked Ed Stone about his reaction to the film, to which Stone replied: “I thought it was a really won­derful idea to take this spacecraft and somehow make it part of a sentient being. Of course, that’s science fiction, but it really does illustrate the impact Voyager’s had on [the] public imagination.”58

The popular conflation of NASA and Star Trek produced a deep cultural narrative about the possibilities of exploring the universe through international and peaceful collaboration. Roddenberry’s altruistic vision of human civilization four hundred years in the future is evidenced in the name chosen for his fictional starship. In deliberate counterpoint to the first nuclear-powered aircraft car­rier, the U. S.S. Enterprise, Roddenberry christened his vessel the United Starship Enterprise and assigned its crew a mission for the peaceful exploration of space.59 Currently, Richard Branson’s Vir­gin Spaceship Enterprise, or VSS Enterprise, is poised to be among the first to offer commercial space tourism flights and is so named in recognition of Star Trek.

There’s a lesson to be gleaned from the history of a low-budget television series, which was cancelled after its third season, that nevertheless has produced such an enduring vision for hu­mankind’s peaceful future. Jon Wagner and Jan Lundeen assert, “Myths are a people’s deep stories—the narratives that structure their worldview.” They point out that Star Trek and its spin-off series frequently drew upon ancient myths to rework them into a modern mythos about equality, regardless of ethnicity or species, and of a future time when humankind organized into a “Federa­tion of Planets has eliminated intolerance, exploitation, greed, war, and materialism.”60 Penley likewise claims that “an astonishingly complex popular discourse about civic, social, moral, and political issues is filtered through the idiom and ideas of Star Trek” and this, in part, explains why the series has been such “a hugely popular story of things to come.”61

In Pale Blue Dot, Sagan wrote: “The visions we offer our chil­dren shape the future. It matters what those visions are.” Cultural narratives, even those spun from fiction, can powerfully shape a generation and a culture’s vision for survival in ages long hence. Among the deeply resonant narratives of space exploration in­forming our generation is Voyager’s epic journey, and Sagan’s apt commentary on the spacecraft’s view of Earth from the edge of our Solar System. “Look again at that dot,” he admonished. “That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. . . . There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. . . . To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.”62

Scientists all along anticipated that tracing our primordial origins with interstellar dust would be like looking for a needle in a hay­stack (or a piece of grit in a gel block). They estimated that, while the side of the collector that faced the comet debris might collect a million particles, they’d be lucky to gather a few dozen from the side trawling for dust from interstellar space. Such was the case. One side of the aerogel was peppered with trails from comet particles, but interstellar dust was very rare, and difficult to spot among all the blemishes and markings that the other side of the aerogel had suffered after seven years in space. Imagine searching for a few dozen ants nestled deep in the grass of a football field. So the two hundred members of the international science team decided to get some help.

Stardust@home has engaged nearly 30,000 members of the public around the world in the search for interstellar dust. The archetypal citizen science project was SETI@home, where the “spare” CPU cycles of millions of PCs were harnessed to analyze chunks of radio data in order to search for transmissions from intelligent aliens.15 SETI@home had distributed computing as a model and no thought or intervention was required by people who participated. Stardust@home is more like Galaxy Zoo, where human eyes and brains are harnessed in pursuit of science goals and participants must undergo training.16 Citizen science is one of the exciting recent developments in outreach and the “democrati­zation” of research, where interested members of the public get on­line training in categorizing and sifting through large amounts of data, and then are able to contribute to the creation of new knowl­edge. Occasionally, these very attentive amateurs make important discoveries.17

The raw material for Stardust@home is a huge number of im­ages made with an optical microscope which can automatically focus at different depths in the aerogel. A set of forty images of a small area are taken with the focus ranging from just above the surface to 100 microns into the aerogel. These images are turned into an animated sequence or “movie” so the viewer seems to move through the aerogel. Altogether, 1.6 million movies were needed to cover the 1,000-square-centimeter surface of the collector. This huge number is part of the reason help was needed. Starting in Au­gust 2006, Stardust “movies” were made available to the general public. Each eager participant first had to undergo a short training session and take a test to show that they could indeed recognize particle tracks. Then they were unleashed on the “haystack.” The signature of a cosmic dust particle is a hollow wake that ends in a tiny particle, often no bigger than a micron in size (figure 6.2). A million such particles ploughed into the aerogel. Of these, only

ten were large enough to see by eye—a tenth of a millimeter or larger—and only one was as big as a millimeter across. Computer programs are unable to reliably identify telltale signs of a particle impact, and they can’t be trained since such detections haven’t yet been made! Additional information has come from the aluminum foil detectors, which were also peppered with dust impacts.18

Citizen scientists can’t get instant gratification from the proj­ect. They have to use the “Virtual Microscope” program in a web browser and report their results to Stardust @home headquarters in Berkeley. Each movie is sent to four users who each scan it in­dependently. Only if a majority of users claim a particle detection does it go to the Stardust science team for confirmation. What do the volunteers get in return for their labors? Mostly online certifi­cates, and the knowledge that they’re contributing directly to an important science mission. Bruce Hudson from Ontario in Canada did a bit better. He had suffered a stroke and turned to the Stardust mission as a good way to pass the large amount of time he had on his hands. Working up to fifteen hours a day for over a year, he not only found the first confirmed interstellar dust particle in the aerogel, he then found a second, named them (Orion and Sirius), and he’ll be a co-author on the paper that results. Hudson might be amused by the irony that astronomers rarely give names to as­teroids or craters less than a kilometer across, yet he put names on objects a billion times smaller. Interstellar dust is distinguished from comet dust by chemical analysis. Particles from deep space are glassy and contain lots of aluminum, along with manganese, nickel, chromium, iron, and gallium. Researchers take particular care not to drop or lose these particles—it would cost $300 million to replace them.

If that seems rather too high-tech and difficult, you can take on the somewhat easier task of gathering comet (and asteroid) dust in the comfort of your own home. Or at least on your roof. Each year 10,000 tons of micrometeorites and 100 tons of space dust land on Earth and a little of that material will also land on the roof of a house. (They’re not recoverable from the ground because they’re too similar to particles in the dirt.) The best scenario is a sloping metal, tin, or slate roof, with no overhanging trees. Col­lect the runoff from a day or more and filter it sequentially with a window screen and then a finer mesh, to remove all leaves, paint flakes, and other artificial materials. The next step involves using a very strong magnet (such as a Neodymium or rare earth magnet, easily obtained by mail order) to gather metallic morsels from the sludge that remains.19

This will isolate the primarily metallic particles, but many ter­restrial forms of debris can be magnetic so the last step involves a hand-held magnifier or cheap microscope. With a magnified view, the rounded, melted, and pitted shape of micrometeorites readily distinguishes them from more mundane terrestrial metal particles. Following this method patiently and carefully will net you a num­ber of particles from deep space, without leaving home, and for a much lower price tag than several hundred million dollars.