The Crowd and the Cosmos: Adventures in the Zooniverse Read online

  The Crowd and The Cosmos

  Praise for The Crowd and the Cosmos

  ‘ The Crowd and the Cosmos is a superbly written insight into the unique and powerful contribution enthusiasts from all walks

  of life can make to scientific knowledge. It is also a fascinating

  and much-needed description of how we acquire reliable

  knowledge about Nature, from the search for planets and

  perhaps civilisations around distant stars to observations of

  Penguins in the Antarctic and what they can teach us about the

  impact we are having on our own world.’

  Brian Cox

  ‘Chris Lintott, is a modest genius. He has quietly revolutionised

  modern Astronomy (and a few other branches of science) by

  using digital platforms to involve the public in processing data.

  Essentially anyone who wants to contribute some of their spare

  time can, and is invited through Chris’s Zoooniverse projects to

  do real science. Literally millions have taken up the invitation.

  This is a beautifully readable book, which tells the story of the

  Zooniverse and much more. Chris is delightfully anecdotal,

  inclusive and witty, yet never shirks in-depth explanations of

  the cutting edge science he’s delivering to us, almost before we

  realise it! This is the New Age of Science for All!!!’

  Brian May

  ‘ The Crowd and the Cosmos gives an authentic flavour of astronomical research and its appeal. But it's especially significant because it

  offers a first-hand account of how Chris Lintott conceived and

  led the “Zooniverse” project, thereby enabling huge numbers

  to participate in significant research, and even make important

  discoveries. His pioneering initiative has spawned similar

  programmes in naval history, conservation, and other subjects—

  triggering a benign social revolution in scholarship and education.’

  Martin Rees

  1

  Great Clarendon Street, Oxford, ox2 6dp,

  United Kingdom

  Oxford University Press is a department of the University of Oxford.

  It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries

  © Chris Lintott 2019

  The moral rights of the author have been asserted

  First Edition published in 2019

  Impression: 1

  All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, by licence or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above

  You must not circulate this work in any other form

  and you must impose this same condition on any acquirer

  Published in the United States of America by Oxford University Press

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  British Library Cataloguing in Publication Data

  Data available

  Library of Congress Control Number: 2018967074

  ISBN 978–0–19–884222–4

  Printed and bound in Great Britain by

  Clays Ltd, Elcograf S.p.A.

  Links to third party websites are provided by Oxford in good faith and for information only. Oxford disclaims any responsibility for the materials contained in any third party website referenced in this work.

  CONTENTS

  Preface

  vii

  1. How Science is Done

  1

  2. The Crowd and the Cosmos

  39

  3. No Such Thing as a New Idea

  73

  4. Into the Zooniverse

  103

  5. Too Many Penguins

  135

  6. From Supernovae to Zorillas

  153

  7. Serendipity

  185

  8. Is it Aliens?

  207

  9. Three Paths

  227

  References

  249

  List of Figure Credits

  255

  List of Plate Credits

  257

  Index

  259

  PREFACE

  There is a faint star, dim and red, which shines feebly in the constellation of Aquarius. You would need a decent telescope

  to see it at all, and in all of humanity’s history of studying the

  Universe no one bothered giving it a name. The star, recorded in

  catalogues as J23154776-1050590, is about 600 light years from

  Earth; not too far on cosmic scales, but close enough that the

  light we see now set off in the early fifteenth century, when King

  Henry V’s English army was fighting the French at Agincourt.

  Andrew Grey is a car mechanic who lives in Darwin, in north-

  ern Australia. He’s also an amateur astronomer with a collection

  of telescopes used for stargazing under the clear desert skies, and

  in April 2016 he was the first person to realize that J23154776-

  1050590 was a star worth keeping an eye on. Every so often, the

  star does something odd. It winks, dimming slightly for an hour

  or two.

  These winks reveal the presence of something that would

  otherwise be hidden. They’re caused by the regular passage of a

  family of planets that happens to cross (or ‘transit’) the face of the star as seen from Earth. The effect is subtle—planets are small

  compared to stars, and a single wink results in a dimming of

  much less than 1 per cent of a star’s brightness—but we can see

  them, and the immutable laws of physics dictate that as a planet

  completes orbit after regular orbit around the star, that single dip

  will be followed by another exactly one orbit later, and another

  and then another, each adding to observers confidence that the

  planet really exists.

  Thanks to Andrew’s ability to notice these small changes in

  brightness, we now know that J23154776-1050590 has at least five

  viii prefaCe

  Figure 1 Artist’s impression of five worlds around K2-138, discovered by citizen scientists in the Exoplanet Explorers project.

  planets in its system. They crowd around the star, now given a

  shorter catalogue number: K2-138 (Figure 1). Nor were these new

  planets just another entry in the rapidly growing planet cata-

  logue. Each is closer to their star than Mercury is to the Sun.

  Packed in tightly, they form a resonant and harmonious pattern,

  each world completing nearly exactly three orbits in the time

  taken for the next one out to go around twice, an arrangement

  which might persist for billions of years and which contains

  within it secrets about these world’s formation.*

  For centuries, and perhaps longer, astronomers dreamt of dis-

  coveries like this. Yet finding new planets, and new solar systems,

&nb
sp; is now something that you can do at home. Andrew’s discovery

  was made not with one of his telescopes, but with a web browser.

  The star was one of many monitored by the Kepler space tele-

  scope, launched and operated by NASA, whose team gave the

  * While editing the book, we were able announce the discovery of a sixth planet which nearly fits the pattern, but is slightly off. Even more intriguing!

  prefaCe ix

  data it collected away for free. A team of astronomers at Caltech

  had looked for likely planets, and shared their analysis online via

  a website that allowed anyone to show up and help. A discovery

  that twenty years ago would have put you in line for the most

  prestigious prizes in science is now something that you, the

  reader of this book, might manage in an otherwise idle lunch

  hour.

  Access to data from telescopes all over the world is now some-

  thing that astronomers take for granted and, as it turns out that

  being open with each other means that we’re also open to the

  world, an increasing number of people are joining us in explor-

  ing the Universe. Consider Despina, an obscure moon of Neptune

  which was first discovered in images taken by the Voyager 2 space probe as it approached the ice giant in the summer of 1989. No

  other probe has passed this way, and so we know very little about

  Despina, other than the fact that it’s small, just 150 kilometres

  across, and that it lives just inside one of the planet’s dark rings.

  It is close enough to Neptune, in fact, that it is probably spiralling slowly inwards, compelled by the push and pull of tides induced

  upon it by the planet’s gravity.

  One day it may fall apart completely, but for now, there it sits.

  Voyager 2 shot through the Neptunian system at high speed, and observations of the planet itself and the largest moon, Triton,

  were the priority. Beyond noting its existence, little was done

  with Despina in the short interval between discovery and fly-

  past, and so all we have had for the last thirty years are a small set of images that make it look like a speckled jelly bean. Voyager’s encounter with Neptune was one of the things that made me, as

  a schoolkid, avidly interested in space, but I can’t say that the

  diminutive moon made much of a mark.

  Despina is part of this story because of some amazing detective

  work done by professional philosopher and amateur astronomer

  x prefaCe

  Ted Stryk. Since Voyager flew past, the best images of both Uranus and Neptune have come from the Hubble Space Telescope, and in 2006 Ted saw a Hubble image which showed one of Uranus’s larger moons, Ariel, transiting the disc. It’s a fun image, with both Ariel

  and its shadow sharp against the pale green disc of the planet,

  and Ted wondered if there were any similar shots from Voyager.

  I would have bet good money on the idea that there was noth-

  ing new to find in the Voyager dataset. Some missions produce enormous libraries of images, with plenty to keep scientists and

  their friends going for decades. The Voyager probes, though, especially when in the outer reaches of the solar system, relied on a

  fairly low bandwidth antenna to get data back to Earth, and so

  relatively few pictures were ever sent. Each image from this

  expensive, once-in-a-lifetime mission, had surely already been

  extensively studied.

  Ted, though, found something new. He got hold of the raw

  data, and used modern technology and his expertise in image

  processing to see something no one else had. In a sequence of

  images taken over the course of nine minutes on 24 August 1989,

  a small black dot can be seen on the planet’s blue, cloud-streaked

  face. In one of the images, and only one, a small bright dot appears

  near the edge of Neptune’s disc.

  This, remarkably, is Despina, caught in transit during the

  Neptune encounter as seen by the speeding Voyager probe

  (Figure 2). The first dot, which appears in the whole sequence, is

  the moon’s shadow, and the second dot the moon itself, just

  entering the disc. It’s a beautiful and poetic set of images, a

  moment in time captured during the only visit of a human-built

  craft to the most distant planet in the Solar System—and it may

  be useful too. Despina’s orbit isn’t well known, and pinning

  down its presence in this particular set of images will help work

  out how it behaves, and what its ultimate fate will be.

  prefaCe xi

  Figure 2 Despina, seen as a bright dot accompanied by its moving

  shadow as seen by Voyager 2 and discovered by Ted Stryk. This is a mon-tage of four images, taken nine minutes apart.

  Despina isn’t an isolated example. Planetary scientists on mis-

  sions to the planets now regularly collaborate with a loose net-

  work of image-processing experts to get the best out of their

  data. When two Mars rovers, Spirit and Opportunity, landed on the red planet in 2004, the team behind them, led by Steve

  Squyres and Jim Bell, made the decision to make the data their

  robot explorers sent back available to the public as soon as it was

  received by NASA. If you happened to refresh the web page at

  just the right time, you could see an image taken on the surface

  of Mars before anyone else on Earth.

  The images have allowed scientists to show that what is now a

  rusty desert was once a wet world. Mars, it’s now clear, once had

  rivers and seas and lakes and oceans. The images from the rovers

  have also fuelled the dreams and fired the imaginations of a com-

  munity of fans back here on Earth, many of whom collaborated

  xii prefaCe

  to make use of the images sent back. This community had time

  (and often, the skills) to do what the scientists could not, making

  colour versions of images, charting their journeys on elaborate

  maps, and creating mosaic views of landscapes and the odd rover

  selfie. When the venerable magazine Aviation Week wanted to put Spirit on their cover, the image they used was created by four outsiders, who collaborated online without ever meeting. (One of

  them, Doug Ellison, a graphic artist from Leicester, now works at

  the Jet Propulsion Laboratory and was part of the team that oper-

  ated the rovers.)

  Whether it’s discovering new worlds or exploring Mars, the

  web allows each of us to be part of the scientific enterprise. It’s

  not just planets either. A distributed network of volunteers have

  spent the last decade sorting through images of galaxies, and

  mapping our own Milky Way. Others have helped conservation-

  ists and scientists study and monitor animals, ranging from lions

  in the Serengeti to coyotes in Chicago (and, lest you think this is

  about exciting, charismatic species, they have also spent time

  looking at many blurry images of kelp off the Californian coast

  and watched videos of egg-laying intestinal worms). Old docu-

  ments, from ancient Greek papyri to the records and letters of

  anti-slavery campaigners in nineteenth-century America, have

  been explored and transcribed by still more volunteers. Hundreds

  of thousands of people have taken part in projects like this; in

  this small corner of the world wide web, together they have con-

  tributed to our u
nderstanding of the world and the cosmos.

  I find it inspiring, and at a time when we tend to talk about the

  internet and the communications revolution it has precipitated

  in mostly negative terms, it’s a reassuring reminder that the vast

  majority of people, both individually and collectively, are good.

  Even when assembled as that most modern of bugbears—a

  crowd on the internet—they are capable of remarkable feats of

  prefaCe xiii

  both generosity and skill. I hope reading this book will inspire

  many people to rush to their nearest screen to try to find a planet

  for themselves—data from NASA’s new planet hunter, the TESS

  satellite, will be flowing in torrents by the time you read this

  book—or, more simply, to take a more personal interest in the

  Universe.

  This book is the story of how I, a distractible astronomer,

  ended up watching all of this activity unfold from a grandstand

  seat. Each of the examples I’ve mentioned so far are from pro-

  jects that live on a platform called the Zooniverse, built by a mer-

  curial and talented team of web developers, scientists, and

  educators which I’ve been proud to lead. I haven’t always had

  space to stop and explain who did what, or how a million con-

  versations led us collectively to solve the problems whose results

  are presented here, but you should be aware as you read that

  everything we’ve been able to achieve in the last few years is the

  result of work by a team full of people much smarter than I.

  It’s very easy to forget when describing a project such as the

  Zooniverse that the technical approach taken is at least as

  important as the science, and in this case everything we’ve done

  has been shaped by early decisions to take both halves equally

  seriously. That we did this was due to Arfon Smith, who was my

  co-conspirator and the technical lead for the Zooniverse’s cru-

  cial early years, and I would be remiss if I didn’t thank him here

  for that insight and all the hard work. Among many others Lucy

  Fortson and Laura Trouille in particular also deserve my grati-

  tude and thanks for their leadership and support. The Galaxy

  Zoo team—particularly Karen Masters and Bill Keel—have

  taught me an enormous amount, and been very tolerant of my

  distractions.