Book Review: “Leaving Orbit” by Margaret Lazarus Dean

First came the Apollo era. Following Sputnik and Yuri Gagarin, the first satellite and human in space, the United States leaped into the space race. Within 11 years of NASA’s formation, and with incredible public support, they managed to launch Neil Armstrong and Buzz Aldrin to the surface of the moon. The moon!

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Then came the space shuttle era, also a time of lofty and grand missions. NASA astronauts flew the shuttles on 135 missions, to deploy space probes like the Hubble Space Telescope and to assemble the International Space Station. But all good things must come to an end, as they say. Margaret Lazarus Dean, in her new book, Leaving Orbit: Notes from the Last Days of American Spaceflight, witnesses and chronicles the final flights of the Discovery, Endeavour and Atlantis shuttles in 2011. For each of those three shuttles, she describes the visceral experience of watching the launches and landings, including the responses of diverse fellow onlookers at Cape Canaveral on the coast of Florida.

Dean reflects on the space shuttle program’s many impressive achievements, as well as its shortcomings and failures, in the case of the tragic explosion of Challenger in 1986 and the breakup of Columbia in 2003. (She previously wrote a novel about the Challenger disaster.) Throughout the book, she provides a record of a wide range of people grappling with the end of the era and wondering about what might come next.

Space shuttle Columbia lifts off from Launch Pad 39A on 12 April 1981. (Credit: NASA)

Space shuttle Columbia lifts off from Launch Pad 39A on 12 April 1981. (Credit: NASA)

She encounters both aspiring and accomplished astronauts—she’s starstruck as she meets Aldrin (and I don’t blame her). Dean also talks to space workers, as well as other writers and journalists, who are all somehow trying to figure how to put these momentous events into words. She makes many references to iconic writers, during what she considers the pinnacle of American spaceflight. Especially Norman Mailer (author of Of a Fire on the Moon), Tom Wolfe (The Right Stuff) and Oriana Fallaci (If the Sun Dies) clearly influenced her.

Dean sprinkles many telling and intriguing anecdotes throughout the book. At one point she quotes a conversation she overheard, in which a NASA public affairs person corrects a Reuters journalist, saying that it’s not the end of American spaceflight, but “the end of American spaceflight as we know it,” which seems to be a subtle distinction. She also points out that in spite of NASA currently accounting for a small fraction of the national budget, her university students overwhelmingly overestimated how much funding the agency actually receives. It gets about 0.4% of the national budget, but most of her students guessed it was more than one fifth! Maybe that demonstrates NASA’s ability to have a big impact and inspire the public imagination with relatively few resources.

NASA's logo, often affectionately referred to as the "meatball." (People refer to its less popular logo in the '80s as the "worm.")

NASA’s logo, often affectionately referred to as the “meatball.” (People refer to its less popular logo in the ’80s as the “worm.”)

Dean’s book is more a memoir than anything else. It’s often fascinating to read, but it feels too wordy and verbose at times. She includes far too many mundane or irrelevant details, including the drive to and from Florida, the motels she stays at (one reference to Mailer is enough there), and numerous texts and social media posts. Omar Izquierdo, a NASA technician, host and new friend, makes for an interesting character, but every single interaction with him doesn’t need to be included. It’s as if she documented in detail every step she took and every thought that popped in her head and shoehorned them in. She also writes many times about her husband and child, who made sacrifices so that she could make these trips; she raises important concerns, but they would belong more in a book more directly touching on work-life balance and gender equality. She and her editors could have cut 100 pages from this book, in my opinion, strengthening its impact without losing any substance.

A few times—maybe a few too many—Dean writes self-referentially about her own book. (Such a device can be effective in a comedy like The Muppet Movie, but I’m not sure how well it works here.) The point, it seems, is to pose a question to herself as much as to others involved in the shuttle program and commercial spaceflight: “I’m asking what it means that we went to space for fifty years and have decided not to go anymore,” she writes.

Dean’s book seems slightly late: it was probably written in 2011 and includes few developments since then. She briefly mentions NASA’s Space Launch System and Orion—scheduled to be launched in an uncrewed mission in 2018—and she describes SpaceX and other spaceflight companies, but this feels tacked on at the end.

I understand her skepticism about commercial spaceflight, and I share many of her concerns. She has three main criticisms: First, the big and daring spaceflight projects that she and many others support are, by definition, not good investments. “They are exploratory, scientific, ennobling, and expensive, with no clear end point and certainly no chance of making a profit.” Second, as long as spaceflight is run by a government agency, she says, any child can reasonably dream of flying in space one day. Third, it’s been part of NASA’s mandate to make its projects available to the public, but private companies have no such obligation.

I don’t think Dean means to diss NASA, but it does seem that way toward the end, as she seems to think ending the shuttle program was a huge mistake. But what’s done is done, and without the shuttle, NASA continues to accomplish a lot. In the past year alone, it deployed a satellite to study Ceres, the only dwarf planet in the asteroid belt; it flung a probe past Pluto, giving us the most detailed images ever of our diminutive cousin; it sent a spacecraft to observe Saturn’s moon Enceladus; and it recently completed a yearlong study of the astronaut twins, Mark and Scott Kelly.

Later in the book, she argues cynically (and to some extent, correctly, in my view) that support for the space program started as an accident, because of Sputnik, a new president, the Cold War, and German rocket designers like Wernher von Braun who fled to the U.S. instead of the Soviet Union.

In the end, however, her reflection turns into an almost obsessive nostalgia for a glorious past. This stifles our ability to take stock of where we are right now and how we got here, and then focus our efforts to plan and prepare for what comes next, which might include returning to the moon, journeying to Mars, and exploring beyond our solar system. Dean’s patriotism limits her too: space exploration requires international collaboration; it isn’t just by or for blue-blooded Americans. It’s for all people who want to join the party, including Russians, Chinese, Europeans, and everyone else.

Mourn the shuttle era in your own way, but then let’s move on with our lives and make the most of our current national and international space programs. We have lots of brilliant, clever and talented people and powerful tools to work with, and if we set our minds to it, our days of exploring space, including launching more people into the skies, will be far from over.

Finding Earth 2.0

In honor of Carl Sagan’s birthday, I figured I’d write a few thoughts I had about a fascinatingly unique conference I attended in the Bay Area last week. It was called “Finding Earth 2.0,” and it was organized by 100 Year Starship, a group partially funded by NASA and the Defense Advanced Research Projects Agency (DARPA) to plan for interstellar travel within the next century.

A potential spacecraft called Icarus Pathfinder would be powered by electric propulsion engines called VASIMR, taking it out to 1,000 times the distance between the Earth and Sun. (Credit: NBC News)

A potential spacecraft called Icarus Pathfinder would be powered by electric propulsion engines called VASIMR, taking it out to 1,000 times the distance between the Earth and Sun. (Credit: NBC News)

Like you might imagine such an organization, the conference speakers and attendees appeared rather eclectic, including astronomers and planetary physicists and science journalists—whom I’m usually hanging out with—as well as aerospace engineers, science fiction writers, business people, teachers, space enthusiasts, and many others. But everyone displayed an active interest in exploring the distant universe and imagining what our future might be like.

Dr. Mae Jemison, the first woman of color in space, heads the 100 Year Starship, and she gave a plenary talk. She pointed to many motivations people have for finding another Earth, including conundrums and challenges our planet and species face, such as limited resources, overpopulation, and our own behavior—perhaps a reference to climate change or nuclear weapons. I think we have many other compelling reasons for interstellar space exploration, but I’ve written about that here before.

I also saw many interesting perspectives and presentations about hunting for planets beyond the solar system, called exoplanets, including habitable ones or even inhabited ones. Dr. Jill Tarter, SETI (Search for Extraterrestrial Intelligence) Institute co-founder and inspiration for Sagan’s protagonist in Contact (Dr. Arroway), gave a provocative presentation on attempts to detect “technosignatures” from distant planets. (She clarified that possessing technology doesn’t imply an intelligent civilization; however, technologies serve as a proxy for intelligence.) Advanced species on these planets could be giving off radio and optical signals that could reach the Earth, but we’d have to listen really really hard to hear them. But if they had a Dyson sphere or an “alien superstructure,” that would be easier.

Other astronomers and astrobiologists talked about their work on related subjects. Margaret Turnbull, also of the SETI Institute, spoke about the “massive harvest” of planets reaped by NASA’s Kepler probe, which confirmed more than 1,000 planets in our Milky Way neighborhood and which showed that about 1 in 5 stars has a planet in the “habitable zone.” Stephen Kane (San Francisco State University) made a convincing case that we should view the habitable zone boundaries as uncertain, and that many planets in the zone would actually be not very hospitable to life. Natalie Batalha (NASA Ames) argued that we should be open-minded about planets in other systems. In one of a few relationship-like quotes, she said, “In our search for a [Earth-like] soul-mate, we may be a bit myopic.” But she was talking about the fact that we have no planets between Earth and Neptune sizes here, while according to Kepler observations, such planets seem rather common throughout the galaxy. She and others also made the point that we need detailed imaging or spectra of planetary systems to learn more about their habitability.

Niki Parenteau (SETI) talked about her efforts to study exoplanets and spot signs of life, which would likely be microorganisms and would have to cover the world to be detectable. “There’s no one smoking gun for biosignatures,” she said. “We need multiple lines of evidence.” She looks for things like biogenic gases and certain planetary surface features. But for her, water is the #1 requirement…and then Morgan Cable, a nerdy joke-telling astrochemist from Jet Propulsion Laboratory, considered a range of other liquids life might be able to develop in, including ammonia, carbon dioxide, petroleum, and liquid hydrocarbons. She ended with her main argument: “NASA shouldn’t just be looking for places with liquid water.”

Artist's illustration of NASA's NEA Scout CubeSat, which is scheduled to launch aboard the maiden flight of the agency’s Space Launch System rocket in 2018. (Credit: NASA)

Artist’s illustration of NASA’s NEA Scout CubeSat, which is scheduled to launch aboard the maiden flight of the agency’s Space Launch System rocket in 2018. (Credit: NASA)

A bunch of people gave presentations about propulsion systems, trying to push the boundaries of space travel. I thought the most interesting one was by Les Johnson, Deputy Manager for NASA’s Advanced Concepts Office at Marshall Space Flight Center. In back-to-back talks, he described current efforts to design and construct giant solar and electric sails. The sails involve ultra-thin reflective materials that are unfurled in space and use solar energy to propel a spacecraft to the distant reaches of the solar system and beyond. In an important step toward that goal, Johnson and NASA engineers are currently building a solar sail for the Near-Earth Asteroid Scout mission to transport a CubeSat “nanosatellite” to study asteroids past Mars in two years. He and his colleagues are also currently testing electric sails for fast solar wind-powered spacecraft, which—if as powerful as hoped—could even send a probe to another star.

Finally, I saw a few strange talks at the conference, and I wasn’t sure what to make of them. For example, one person spoke about the new field of “astrosociology.” He avoided giving any specifics though, even though he had been discussing “deviant” behavior, and admitted after the talk that he had envisioned studying multi-year trips transporting tens of thousands of colonists beyond the solar system. Maybe for the 200 Year Starship! Unfortunately, the speaker had not considered small missions, such as handfuls of astronauts traveling to Mars or private ventures conducting asteroid mining. I’d imagine that such small groups of people stuck together for long periods could benefit from sociological study.

Book Review: Five Billion Years of Solitude

As long as humans have roamed the Earth, they have looked up to the skies, speculating and pondering about the celestial wonders populating the distant cosmos. From the early astronomers and natural philosophers until today’s (including me), people have observed and studied the billions of twinkling dots, all the while wondering whether there are other worlds out there and whether they might host lifeforms like us.

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In his first book, “Five Billion Years of Solitude: The Search for Life Among the Stars,” Lee Billings explores these and related questions. He chronicles the story of space exploration, planet-hunting and the growing field of astrobiology, while meeting fascinating characters and discussing their research, telescopes, discoveries and challenges. He offers clear and compelling explanations, such as of planetary physics and habitability, and he takes important asides into debates on space exploration budgets and the fate of our own planet, including the ongoing climate change crisis.

Billings is a talented science journalist. Like his work for Scientific American and other publications, the book is excellently written and researched. It won the 2014 American Institute of Physics science communication award in the book category, announced at the American Astronomical Society meeting in January.

Over the course of the book, Billings tracks down and speaks with important figures in planetary astronomy. He begins with Frank Drake, who along with nine other scientists in 1961 attempt to quantify the abundance of life-supporting planets in the galaxy in a calculation now known as the Drake Equation. He also meets with other astrophysicists, including University of California, Santa Cruz professor Greg Laughlin, Space Telescope Science Institute director Matt Mountain and MIT professor Sara Seager.

Since the time-scale or life-time of civilizations plays a role in the Drake Equation, his investigations lead to an examination of our own history and the longevity of humanity on Earth. Billings discusses the planet’s changing climate and other looming threats, for which our society appears unprepared. His reporting takes him to southern California too, where he quotes from my former colleague, UC San Diego physicist Tom Murphy, who considered the question of growing global energy consumption.

Other important questions come up as well. How far away are planets beyond our solar system and how long would it take to get there? What kind of atmospheric, geological and climatic conditions must a habitable planet have? How do astronomers detect planets, when they are so small, so faint and so close to their brightly glowing suns? What are our prospects for finding more Earth-like planets?

And what will happen to the Earth and humankind—if we’re still around—over the next few billion years, as our sun brightens, expands and transforms into a red giant star? As Billings starkly puts it in his interview for The Atlantic, “We may have—we may be—the only chance available for life on Earth to somehow escape a final, ultimate planetary and stellar death.”

Artist's conception of NASA's Kepler spacecraft. (Image credit: NASA/Ames/JPL-Caltech)

Artist’s conception of NASA’s Kepler spacecraft. (Image credit: NASA/Ames/JPL-Caltech)

With the Kepler telescope, we have the good fortune to be living at a time when actually Earth-like worlds, not just super-Earths and gas dwarfs, can be identified. Astronomers have already used the telescope to find a few potential Earth cousins, which have the right size and the right “Goldilocks” distance from their stars, and many many more candidates are on the horizon. Under certain conditions, follow-up observations can measure the planets’ atmospheres and climates to further assess their habitability.

It’s an exciting time! With even more advanced planet-finding telescopes coming up, such as the Hubble successors, the James Webb Space Telescope and High-Definition Space Telescope, we can look forward to more detailed images and observations of exoplanets in the near future. Maybe Earth has twins and maybe we are not alone.

I have a few criticisms of Five Billion Years, but they’re very minor ones. I liked the analysis of federal budget debates at multiple points in the book, but Billings could have written a little more about why as a society we should prioritize space exploration and astronomical research. If, say, a member of the House Science Committee (or more likely, their staffer) were to read this, it would be helpful to spell that out. Early in the book, he provides an engaging historical survey of astronomy, but he neglected Eastern contributions, such as from Persians, Arabs and Chinese. A few chapters meandered quite a bit too, but I enjoyed his writing style.

In any case, this is a beautifully written and thoroughly researched book, and I recommend it. Billings puts the search for extraterrestrial life in a broader context and pushes us to think about our place in the vast universe. The story continues.

[P.S. I’m extremely busy these days with the UC Santa Cruz science communication program and writing internships, so I may write posts here less often. But I will link to pieces I’ve written elsewhere, which have the benefit of rigorous editing, so if you like my blog, you’ll like them even more.]

Why do we engage in space exploration?

A review of diverse perspectives on space exploration and extraterrestrial life reveal fundamentally human hopes, fears and flaws

Since the dawn of civilization thousands of years ago, humans have looked to the skies. Archaeologists have found evidence of people from China, India, and Persia to Europe and Mesoamerica observing and contemplating the many stars and planets that fascinated them. We humans have also wondered about—and often hoped for—the existence of other intelligent life out there. Considering the large number of planets in the Milky Way and in billions of other galaxies, perhaps we are not alone, and maybe even while you are reading this, extraterrestrials could be looking in our direction through their telescopes or sending us interstellar telegrams. But if our galaxy teems with aliens, following Italian physicist Enrico Fermi’s persistent question, we must ask, “Where are they?”

Artist's depiction of a travel poster for a "Tatooine-like" planet orbiting two suns, recently discovered by NASA's Kepler spacecraft. (Courtesy: NASA)

Artist’s depiction of a travel poster for a “Tatooine-like” planet orbiting two suns, recently discovered by NASA’s Kepler spacecraft. (Courtesy: NASA)

Two recent pieces in the New Yorker and New York Times, as well as numerous books over the past couple years, motivate me to consider this and related questions too. Astronomers and astrophysicists around the world, including scientists working with NASA, the European Space Agency (ESA), the Japanese Space Agency (JAXA) and many others, have many varieties of telescopes and observatories on Earth and in space, just because we want to investigate and learn about our galactic neighborhood and beyond. We also attempt to communicate, like sending a message in a bottle, with the Golden Records aboard the Voyager spacecrafts, and we listen for alien attempts to contact us. In our lifetime, we have dreams of sending humans to Mars and to more distant planets. Why do we do this? We do it for many reasons, but especially because humans are explorers: we’re driven to see what’s out there and to “boldly go where no one has gone before.” As Carl Sagan put it in Cosmos, “Exploration is in our nature. We began as wanderers, and we are wanderers still.”

Views of human space exploration

Elizabeth Kolbert reviews three recently published and forthcoming books by Chris Impey, an astronomer at the University of Arizona (where I used to work three years ago), Stephen Petranek, a journalist at Discover, and Erik Conway, a historian of science at Jet Propulsion Laboratory. (She did not mention an award-winning book by Lee Billings, Five Billion Years of Solitude, which I will review in a later post.) She fault finds with the overoptimistic and possibly naïve “boosterism” of Impey and Petranek. “The notion that we could…hurl [humans]…into space, and that this would, to use Petranek’s formulation, constitute ‘our best hope,’ is either fantastically far-fetched or deeply depressing.” She asks, “Why is it that the same people who believe we can live off-Earth tend to believe we can’t live on it?”

Kolbert’s assessment has some merit. Astrophiles and space enthusiasts, of which I am one, sometimes seem to neglect Earth (and Earthlings) in all its wonder, marvels, complexity, brutality and messiness. But is the primary reason for exploring the universe that we can’t take care of ourselves on Earth? Mars should not be viewed as a backup plan but rather as one of many important steps toward better understanding our little corner of the galaxy. Furthermore, we should be clear that sending humans to Mars and more distant worlds is an incredibly complicated and dangerous prospect, with no guarantee of success. Even if the long distances could be traversed—at its closest, Mars comes by at least a staggering 50 million miles (80 million km) away, and then the nearest star, Alpha Centauri, is about 25 trillion miles from us—future human outposts would face many obstacles. The popular novel by Andy Weir, The Martian, demonstrates only some of the extraordinary challenges of living beyond our home planet.

Overview of components of NASA's Journey to Mars program, which seeks to send humans to the red planet in the 2030s. (Credit: NASA)

Overview of components of NASA’s Journey to Mars program, which seeks to send humans to the red planet in the 2030s. (Credit: NASA)

Though Kolbert criticizes Conway’s dry writing style, she clearly sympathizes with his views. “If people ever do get to the red planet—an event that Conway…considers ‘unlikely’ in his lifetime—they’ll immediately wreck the place just by showing up…If people start rejiggering the atmosphere and thawing the [planet’s soil], so much the worse.” This line of criticism refers to flaws of geoengineering and of the human species itself. Many times in history, humans ventured out acting like explorers, and then became colonists and then colonialists, exploiting every region’s environment and inhabitants.

Note that Kolbert is a journalist with considerable experience writing about climate, ecology and biology, while astrophysics and space sciences require a stretch of her expertise. In her excellent Pulitzer Prize-winning book, The Sixth Extinction, Kolbert argues provocatively that humans could be viewed as invasive species transforming the planet faster than other species can adapt, thereby constituting a danger to them. “As soon as humans started using [language], they pushed beyond the limits of [the] world.” I agree that humans must radically improve their relationship with nature and Earth itself, but this does not preclude space travel; on the contrary, the goal of exploring other worlds should be one aspect of our longer-term and larger-scale perspective of humanity’s place in the universe.

Views of extraterrestrial intelligence

Dennis Overbye, a science writer specializing in physics and astronomy, covers similar ground, but focuses more on the search for extraterrestrial intelligence (SETI). He mentions the Drake Equation, named after the American astronomer Frank Drake, which quantifies our understanding of the likelihood of intelligent life on other planets with whom we might communicate. Both Drake and Sagan “stressed that a key unknown element in their equations was the average lifetime of technological civilizations.” If advanced species don’t survive very long, then the possibility of contact between overlapping civilizations becomes highly improbable. It would be unfortunate if similarly advanced civilizations, like Earthlings and Klingons, could never meet.

Overbye introduces the controversial University of Oxford philosopher, Nick Bostrom, who is rooting for us to fail in our search for ETs! “It would be good news if we find Mars to be sterile. Dead rocks and lifeless sands would lift my spirit.”

Bostrom bases his argument on a concept he refers to as the Great Filter. Considering the likelihood of advanced civilizations, many conditions and criteria must be satisfied and steps must be taken before a planet in the “habitable zone” has a chance of harboring intelligent life. The planet probably must have the right kind of atmosphere and a significant amount of liquid water and some kind of possibly carbon-based building blocks of life, and after that, the alien species’ evolutionary developments could go in any direction, not necessarily in a direction that facilitates intelligence. In addition, asteroids, pandemics, or volcanic eruptions could wipe out this alien life before it got anywhere. In other words, myriad perils and difficulties filter out the planets, such that only a few might have species that survive and reach a level of social and technological advancement comparable to those of humans.

On the other hand, if we do find life on other planets and if intelligent extraterrestrial life is relatively ubiquitous, our lack of contact with them could mean that advanced civilizations have a short lifetime. Perhaps the Great Filter is ahead of us, “since there is no reason to think that we will be any luckier than other species.” Maybe nuclear war, climate change, or killer robots might wipe us out before we have the chance to explore the galaxy.

I am not convinced by Bostrom’s pessimism. Even if the Great Filter is ahead of us, implying that humans face more existential threats in the future than have been overcome in the past, this doesn’t mean that we are doomed. Humanity does have major problems with acknowledging large-scale impacts and long-term outlooks, but I hope we could learn to change before it is too late.

A more positive outlook

We have learned a lot about planets, stars, galaxies, black holes and the distant universe from our tiny vantage point. But we would be immodest and mistaken to brazenly presume that we’ve already figured out the rest of the universe. We really don’t know how many other “intelligent” species might be out there, and if so, how far they are, what level of evolution they’re at (if evolution is a linear process), or whether or how they might communicate with us. We should continue to discuss and examine these questions though.

While traveling to other planets will take a long time, in the meantime astronomers continue to make exciting discoveries of possibly “Earth-like” planets, such as Kepler-452b, an older bigger cousin to our world. It seems likely that the Earth has a very big family, with many cousins in the Milky Way alone.

So why do we engage in space exploration and why do we seek out extraterrestrial life? This question seems to transform into questions about who we are and how we view our role in the universe. I believe that humans are fundamentally explorers, not only in a scientific sense, and we have boundless curiosity and wonder about our planet and the universe we live in. Humans also explore the depths of the oceans and dense rainforests and they scour remote regions in arid deserts and frigid glaciers (while they still remain), just to see what they’re like and to look for and observe different lifeforms.

More importantly, even after tens of thousands of years of human existence, we are still exploring who we are, not just with scientific work by psychologists and sociologists but also with novelists, poets and philosophers. We still have much to learn. To quote from Q, a capricious yet occasionally wise Star Trek character, “That is the exploration that awaits you: not mapping stars and studying nebulae, but charting the unknown possibilities of existence!”

High-Definition Space Telescope: Our Giant Glimpse of the Future?

Where do you see yourself in a decade? What is your vision for two decades from now? What could you accomplish if you had billions of dollars and infrastructure at your disposal? A consortium of astrophysicists attempt to answer these questions as they put forward their bold proposal for a giant high-resolution telescope for the next generation, which would observe numerous exoplanets, stars, galaxies and the distant universe in stunning detail.

Artist’s conception of proposed proposed High-Definition Space Telescope, which would have a giant segmented mirror and unprecedented resolution at optical and UV wavelengths. (NASA/GSFC)

Artist’s conception of proposed proposed High-Definition Space Telescope, which would have a giant segmented mirror and unprecedented resolution at optical and UV wavelengths. (NASA/GSFC)

The Association of Universities for Research in Astronomy (AURA), an influential organization of astronomers from 39 mostly US-based institutions, which operates telescopes and observatories for NASA and the National Science Foundation, lays out its vision of High-Definition Space Telescope (HDST) in a new report this month. Julianne Dalcanton of the University of Washington and Sara Seager of the Massachusetts Institute of Technology—veteran astronomers with impressive knowledge and experience with galactic and planetary science—led the committee who researched and wrote the 172-page report.

As the HDST’s name suggests, its wide segmented mirror would give it much much higher resolution than any current or upcoming telescopes, allowing astronomers to focus on exoplanets up to 100 light-years away, resolve stars even in the Andromeda Galaxy, and image faraway galaxies dating back 10 billion years of cosmic time into our universe’s past.

A simulated spiral galaxy as viewed by Hubble and the proposed High Definition Space Telescope at a lookback time of approximately 10 billion years. Image credit: D. Ceverino, C. Moody, G. Snyder, and Z. Levay (STScI)

A simulated spiral galaxy as viewed by Hubble and the proposed High Definition Space Telescope at a lookback time of approximately 10 billion years. Image credit: D. Ceverino, C. Moody, G. Snyder, and Z. Levay (STScI)

In the more recent past, the popular and outstandingly successful Hubble Space Telescope celebrated its 25th birthday a few months ago. Astronomers utilized Hubble and its instruments over the years to obtain the now iconic images of the Crab Nebula, the Sombrero Galaxy, the Ultra Deep Field, and many many others that captured the public imagination. Hubble continues to merrily float by in low-earth orbit and enables cutting-edge science. But the telescope required 20 years of planning, technological development, and budget allocations before it was launched in 1990.

For the newly proposed space telescope, some headlines describe it as NASA’s successor to Hubble, but it really constitutes a successor to a successor of Hubble, with other telescopes in between (such as the Wide-Field InfraRed Survey Telescope, WFIRST). If the astronomical community comes on board and if astronomers convince NASA and Congressional committees to fund it—two big “ifs” for big projects like this—it likely would be designed and constructed in the 2020s and then launched in the 2030s.

The James Webb Space Telescope (JWST), proposed two decades ago by AURA and now finally reaching fruition and set for launching in 2018, could be considered the HDST’s predecessor. All of these major projects require many years of planning and research; Rome wasn’t built in a day, as they say. James Webb scientists and engineers hope that, like Hubble, it will produce spectacular images with its infrared cameras, become a household name, and expand our understanding of the universe. Nevertheless, JWST has been plagued by a ballooning budget and numerous delays, and Congress nearly terminated it in 2011. When a few large-scale programs cost so many billions of dollars and years to develop, how do people weigh them against many smaller-scale ones that sometimes get sacrificed?

Approximately every ten years, members of the astronomical community get together and determine their set of priorities for the next decade, balancing large-, medium- and small-scale programs and ground- and space-based telescopes, given the budget realities and outlook. Back in 2001, they prioritized James Webb, and then a decade later they put WFIRST at the top of the list. For the next generation though, in the 2010 Decadal Survey (named “New Worlds, New Horizons”), they highlighted the need for a habitable (exo)planet imaging mission. Everyone loves planets, even dwarf planets, as revealed by the popularity of NASA’s missions exploring Pluto and Ceres this year.

Building on that report, NASA’s 2014 Astrophysics Roadmap (named “Enduring Quests, Daring Visons”) argued that much could be gained from a UV/optical/infrared surveyor with improved resolution, which could probe stars and galaxies with more precision than ever before. According to the AURA committee, the High-Definition Space Telescope would achieve both of these goals, taking planetary, stellar and galactic astronomy to the next level. Importantly, they also argued that astronomers should prioritize the telescope in the 2020 Decadal Survey, for which planning has already commenced.

How do scientists balance the need for different kinds and sizes of projects and missions, knowing that every good idea can’t be funded? Astronomers frequently disagree about how to best allocate funding—hence the need for periodic surveys of the community. They hope that what is best for science and the public will emerge, even if some scientists’ favorite projects ultimately aren’t successful. James Webb Space Telescope’s budget has been set to $8 billion, while the High-Definition Space Telescope would cost $10 billion or more, according to Alan Dressler of the Carnegie Observatories. This is big money, but it’s small compared to the cost of bank bailouts and military expenditures, for example. While the scientific community assesses which programs to focus on, we as a society need to determine our own priorities and how space exploration, astrophysics research as well as education and outreach are important to us. In the meantime, HDST scientists will continue to make their case, including in an upcoming event at the SPIE Optics & Photonics conference in San Diego, which I will try to attend.

Scientists and journalists alike frequently talk about Big Science these days. The recently published and much reviewed book by Michael Hiltzik about the physicist Ernest Lawrence describes its history since the Manhattan Project and the advent of ever-bigger particle accelerators. Big Science is here to stay and we clearly have much to gain from it. Only some Big Science ideas can be prioritized and successfully make the most of the effort and investment people put in them. Hubble exceeded all expectations; the High-Definition Space Telescope has astronomical shoes to fill.

New Discoveries as New Horizons Flies by Pluto!

You may be wondering, what’s the deal with Pluto? First, astronomers demote Pluto’s planetary status in a controversial move, to say the least, and then NASA sends a spacecraft on a mission to observe it in detail? Why is this important, and what could we learn about Pluto that we didn’t know already?

Image from the Long Range Reconnaissance Imager (LORRI) aboard NASA's New Horizons spacecraft, taken on 13 July 2015. Pluto is dominated by the feature informally named the "Heart." (Image Credit: NASA/APL/SwRI)

Image from the Long Range Reconnaissance Imager (LORRI) aboard NASA’s New Horizons spacecraft, taken on 13 July 2015. Pluto is dominated by the feature informally named the “Heart.” (Image Credit: NASA/APL/SwRI)

Of course, we have quite a bit to learn. Moreover, as one of the least studied objects in the outer regions of our solar system, Pluto is ripe for exploration and investigation. Within a few days, NASA’s New Horizons probe already produced detailed and exquisite photos of Pluto, much better than has been done with Hubble or any other telescope. Its mission is far from over, but it’s already an amazing success and has inspired public interest in space exploration once again.

Back in 1930, 85 years ago, a young astronomer by the name of Clyde Tombaugh at Lowell Observatory in Flagstaff, Arizona noticed a distant possibly planet-like object moving across photographic plates. When other astronomers confirmed the discovery, thousands of people suggested names for the planet. In the end, the name that caught on in the community came from an 11-year-old girl in Oxford, Venetia Burney, and the Lowell astronomers approved “Pluto” unanimously. (Contrary to some rumors, she did not name it after the cartoon dog.) Burney (later Phair) lived to witness the launching of New Horizons, but she passed away in 2009. Some of Tombaugh’s ashes are aboard the spacecraft, and his children and grandchildren were present for the events of New Horizons.

NASA's New Horizons spacecraft.  (Artist's impression.)

NASA’s New Horizons spacecraft.
(Artist’s impression.)

NASA’s New Horizons spacecraft launched from Cape Canaveral in January 2006. Its journey took it 3 billion miles (about 5 billion km) from Earth, including a slingshot around Jupiter—covering nearly 1 million miles per day!—to reach Pluto. To paraphrase Douglas Adams, you may think it’s a long way to the chemist’s, but that’s just peanuts compared to the distance New Horizons traveled. Principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado leads the mission, which also includes a relatively large fraction of women on the team. In another important point, the mission had a relatively small cost ($700M) considering its huge impact on planetary physics, space exploration, and science outreach.

Once Pluto was demoted (or even dissed) by the astronomical community back in 2006, it’s never been more popular! New Horizons’ flyby only rekindled interest in Pluto in popular culture. I’ve seen many comics, memes and jokes about it, including XKCD, a cartoon showing Neil deGrasse Tyson and Pluto giving each other the finger, a cartoon with a sad Pluto as New Horizons flies by while saying “HEYWHATSUPGOTTAGOBYE!,” and another cartoon with Pluto saying, “So you dumped me years ago, but now you’re driving by my house real slow?”

As I wrote in a previous post, Pluto has many characteristics, including its small size and mass, that give it a questionable planetary status. It is one of many objects hurtling about the edge of our solar system called the Kuiper Belt, named after Dutch-American astronomer Gerard Kuiper. According to the International Astronomical Union (IAU), these are some of the solar system’s non-planets, ranked by size: Ganymede (Jupiter moon), Titan (Saturn moon), Callisto (Jupiter moon), Io (Jupiter moon), Earth’s moon, Europa (Jupiter moon), Triton (Neptune moon), Pluto, and Eris. Much further down the list comes Ceres (in the asteroid belt between Mars and Jupiter), which is actually smaller than Charon, one of Pluto’s moons. Eris, which was previously known as 2003 UB313 (and also as Planet X, and then Xena, as in the Warrior Princess) is slightly more massive than Pluto. In addition to Pluto, Eris, and Ceres, Haumea (a trans-Neptunian object) and Makemake (another Kuiper Belt object) are the other two dwarf planets the IAU recognizes. In any case, Pluto may be small and may be less unique than we thought and may have an abnormally elliptical orbit, but we all love it anyway.

New Horizons made its closest approach on 14 July, Tuesday morning, about 50 years after the first spacecraft landed on Mars, Mariner 4. It will take many months for New Horizons to transmit all of the Pluto flyby data back to Earth, but what has the probe discovered so far? First, New Horizons already obtained the most detailed images of Pluto ever. Second, based on the imagery, astronomers calculated that Pluto is slightly larger than previously thought: it turns out to have a radius 1.9% larger than Eris’s, making it the largest dwarf planet.

New Horizons scientists also found that Pluto is icier than previously thought, with its polar ice cap and with icy mountains nearly as high as the Rockies. The ice consists of a frozen mixture of methane, ethane, carbon monoxide and nitrogen—not the sort of thing you’d want to put in a drink. Pluto’s mountains likely formed less than 100 million years ago, which is a relatively short time in the history of a (dwarf) planet. At least some of Pluto’s surface might still be geologically active today—some scientists think they have spotted potential geysers as well—but planetary physicists are not sure about what could have caused this activity. Furthermore, Pluto exhibits very few impact craters from Kuiper belt objects (KBOs), which would also be consistent with recent geological activity.

Charon also lacks such craters—a surprising observation considering that it appears to have no atmosphere. Charon’s diameter is over half of Pluto’s, which makes it big enough to cause Pluto to wobble as it orbits. Scientists believe that Charon likely formed from a huge collision with a young Pluto, and debris also settled into Pluto’s four other moons: Nix, Hydra, Kerberos, and Styx. Alternatively, Pluto could have gravitationally captured Charon a few hundred million years ago, which could explain the “tidal interactions” between them.

Finally, New Horizons astronomers discovered vast frozen craterless plains in the center of Pluto’s “heart,” which they have informally named the “Tombaugh Regio.” The plains region has a broken surface of irregularly-shaped segments that either may be due to the contraction of surface materials, like when mud dries, or may be the result of convection. The New Horizons team released the following zoom-in images at a press conference today, and we expect more to come.

What’s next for New Horizons? The probe continues to send more valuable data from its seven instruments in our general direction. Project scientists will sift through these data to try to learn more about Pluto and Charon’s surface, geology, and atmosphere, and therefore to infer how these interesting objects formed and evolved. In the meantime, New Horizons continues on its merry way throughout the Kuiper Belt. Assuming NASA approves funding for its extended mission, in a couple years it will use its limited fuel to investigate much smaller and newly discovered KBOs, such as 2014 MT69. In any case, we shall keep in touch with New Horizons as it follows the Voyager spacecrafts into the outskirts of our solar system and boldly ventures beyond.

[For further reading, you can find great coverage about these exciting discoveries in many places. For example, take a look at Nature (Alexandra Witze), Science, Scientific American, National Geographic (Nadia Drake), Wired, NBC (Alan Boyle), as well as New York Times, Los Angeles Times, Guardian, BBC, etc… For the most up-to-date information, I suggest taking a look at NASA’s website and the Planetary Society (Emily Lakdawalla).]