The Search for Planets Around Other Stars
An Introductory Resource Guide for College Instructors
Updated May 2014
About the Guide
The discovery and characterization of exoplanets is one of the most exciting and fast-changing areas in modern astronomical research. As a result, Astronomy 101 instructors have had trouble keeping up with the flow of new techniques, instruments and discoveries. To help, NASA missions, educational projects around the country, and scientists themselves have produced a wide range of materials that astronomy instructors (and their students) can use to learn about the latest developments. This annotated guide is designed to highlight useful materials on the web and in print. It was produced in consultation with NASA education specialists, who suggested some resources that may not have been well known.
We include only those non-technical materials that instructors around the U.S. are likely to have access to. This guide includes only a sampling of non-technical materials that instructors around the U.S. have been using and are likely to have access to. Items were selected based on their level of difficulty (Astro 101 level and below), the likelihood of easy access by a college audience, and their potential usefulness for teaching and learning. Additions and comments are more than welcome and can be directed to: Greg Schultz: gschultz {at} astrosociety.org and Bonnie Meinke: Meinke {at} stsci.edu
We welcome your feedback! Please complete a short questionnaire at http://www.surveymonkey.com/s/ExoplanetResourceGuide so we may better understand who is using the guide, in what settings, and how. Thank you in advance for your feedback.
Compiled by: Andrew Fraknoi (Foothill College)
Coordination: NASA Astrophysics Science Education and Public Outreach Forum
TABLE OF CONTENTS:
Web Sites for the General Reader
A Few Web-based Articles
Popular-level Books
Selected Current Print Articles
Selected Audio Files on the Web
Selected Video Files on the Web
Educational Resources, Outreach Materials, Citizen Science
Apps for Smartphones and Tablets
Notes and Acknowledgements
ò×Ê NASA education product reviewed materials
The NASA Earth & Space Science Education Product Review evaluates NASA Science Mission Directorate funded educational materials via peer-review by a panel of scientists and educators. Web sites with this symbol contain education materials developed for classroom use that have passed the NASA Earth & Space Science Education Product Review. The web site may also contain outreach resources that may be of interest to the reader.
Web Sites for the General Reader
ArtistòÀÙs conception of the Kepler-10 system, which has two Super Earths in close orbits around their host star. The larger planet, Kepler-10c, is in the foreground and the smaller Kepler-10b transits the host star in the background. (Credit: NASA/Ames/JPL-Caltech/T. Pyle)
NASA Sources:
ò×Ê PlanetQuest (from the Exoplanet Exploration Program at the Jet Propulsion Lab), for students and beginners, includes introductory materials and illustrations; it focuses mostly on NASA work and missions: http://planetquest.jpl.nasa.gov/
ò×Ê The Kepler Mission Web Site: http://kepler.nasa.gov/ is the public web site for the telescope in space that is searching for planets using the transit technique and is currently our best hope for finding earth-like planets.
Other Sources:
The Extra-solar Planets Encyclopedia, maintained by Jean Schneider of the Paris Observatory, has the largest catalog of planet discoveries and useful background material (some of it more technical): http://exoplanet.eu/
The Planetary Society Exoplanets Pages have a dynamic catalog of planets found and explanations: http://www.planetary.org/exoplanets/
The California Planet Search site highlights the work of the original American team of planet hunters (Marcy and Butler) and their colleagues, and has useful general background information as well: http://www.exoplanets.org/cps.html
Pulsar Planets is a brief introduction to the very first planet discoveries, planets around the corpses of dead stars called neutron stars: http://www.astro.psu.edu/users/alex/pulsar_planets.htm
The Exoplanet Data Explorer is an interactive table and plotter for exploring and displaying data from the Exoplanet Orbit Database that keeps up with the published characteristics of the planets found so far (a bit more technical): http://www.exoplanets.org
The Visual Exoplanets Catalogue is a òÀÜtoolkitòÀÝ for visualizing and organizing information about planets out there http://exoplanet.hanno-rein.de (This is for people with a bit more background) You can also get an òÀÜExoplanetòÀÝ app for your iPhone/iPad; see last section.)
The Habitable Exoplanet Catalog is a page that lists and describes those planets that are in the habitable zone of their stars (from the University of Puerto Rico): http://phl.upr.edu/projects/habitable-exoplanets-catalog
The Habitable Zone Gallery (somewhat more advanced) shows plots, tables, movies, and charts of the habitable zone around stars with planets and where the known planets are relative to that zone: http://www.hzgallery.org/
A Few Web-based Articles
The Keck I primary mirror assembly made of 36 hexagonal mirror segments. The Keck telescopes have been used to track the radial velocity Doppler shift of stars as a means to detect the planets that orbit them. (Courtesy W. M. Keck Observatory)
A brief introduction to extrasolar planets for beginners from the PBS Seeing in the Dark special: http://www.pbs.org/seeinginthedark/astronomy-topics/extrasolar-planets.html
Bell, E. òÀÜSeven Amazing ExoplanetsòÀÝ (from Scientific American magazine, with art by Ron Miller, this brief set of pages features artistòÀÙs impressions of seven other planetary systems): http://www.scientificamerican.com/article.cfm?id=7-amazing-exoplanets-interactive (This is part of an app for iPads called Journey to the Exoplanets): http://www.the-exoplanets.com/
Thaller, M. òÀÜProbing Extrasolar Planets with the Spitzer Space TelescopeòÀÝ (an issue of the ASPòÀÙs Universe in the Classroom Newsletter (2009): http://www.astrosociety.org/education/publications/tnl/75/75.html
Gould, A. òÀÜThe Kepler MissionòÀÝ (from The Universe in the Classroom): http://www.astrosociety.org/education/publications/tnl/76/76.html (Spring 2010)
Exoplanets: The Search for Planets Beyond Our Solar System (from the British Institute of Physics in 2010): http://www.iop.org/publications/iop/2010/page_42551.html
Popular-level Books
This diagram compares our solar system to Kepler-22, a star system containing the first òÀÜhabitable zoneòÀÝ planet discovered by NASAòÀÙs Kepler mission. Kepler-22òÀÙs star is a bit smaller than our sun, so its habitable zone is slightly closer in. The diagram shows an artistòÀÙs rendering of the planet comfortably orbiting within the habitable zone, similar to where Earth circles the sun. Kepler-22b has a yearly orbit of 289 days. The planet is among the smallest known to orbit in the middle of the habitable zone of a sun-like star. ItòÀÙs about 2.4 times the size of Earth. (Image credit: NASA/Ames/JPL-Caltech)
Boss, Alan. The Crowded Universe: The Search for Living Planets. 2009, Basic Books. A book brimming with optimism (and also full of information) about the prospects of finding Earth-like worlds out there.
Casoli, Fabinee & Encrenaz, Therese. The New Worlds: Extrasolar Planets. 2007, Springer. Translated from the Italian edition, this is an illustrated guide to how we are discovering exoplanets.
Jayawardhana, Ray. Strange New Worlds: The Search for Alien Planets and Life Beyond Our Solar System. 2011, Princeton U. Press. Clear overview by an astronomer and popular writer.
Jones, Barrie. The Search for Life Continued: Planets around Other Stars. 2008, Praxis/Springer. An introductory book by a British astronomer.
Kasting, James. How to Find a Habitable Planet? 2009, Princeton U. Press. A primer on planet searches, ideas about habitable planets, and astrobiology.
Lemonick, Michael. Mirror Earth: The Search for Our PlanetòÀÙs Twin. 2012, Walker & Co. Introduction to the discovery of exoplanets, with profiles of key scientists, by a science journalist.
Mayor, Michel & Frei, Pierre-Yves. New Worlds in the Cosmos: The Discovery of Exoplanets. 2003, Cambridge U. Press. This is a translation of the 2001 French book, written by the co-discoverer of the first planet found out there and a science journalist.
Wittenstein, Vicky. Planet Hunter: Geoff Marcy and the Search for Other Earths. 2010, BoydòÀÙs Mill Press. A childrenòÀÙs book for 5th òÀÓ 7th grade level that profiles a prominent American exoplanet discoverer.
Selected Current Print Articles
Coronagraph of the star Fomalhaut surrounded by a ring of dust. An inset image zooms in on part of the ring where planet Fomalhaut b was seen at different parts of its orbit in 2004 and 2006. (Credit: NASA, ESA and P. Kalas )
Overview Articles
Carlisle, C. òÀÜThe Race to Find Alien EarthsòÀÝ in Sky & Telescope, Jan. 2009, p. 28. On early discoveries of planets with masses comparable to EarthòÀÙs and on the Kepler mission to find many more of them.
Cooper, K. & Baldwin, E. òÀÜFocus: ExoplanetsòÀÝ in Astronomy Now, Nov. 2009, p. 63. Concise introduction to the techniques and some of the most interesting planets found so far.
Fischer, D. òÀÜHow Astronomers Will Find Another EarthòÀÝ in Astronomy, Oct. 2010, p. 28. On what would constitute òÀÜanother EarthòÀÝ and how we are trying to find such worlds.
Johnson, J. òÀÜThe Stars That Host PlanetsòÀÝ in Sky & Telescope, Apr. 2011, p. 22. Examines what we are learning about the stars that are known to have planets.
Marcy, G. òÀÜThe New Search for Distant PlanetsòÀÝ in Astronomy, Oct. 2006, p. 30. A 7-page overview by co-discoverer of hundreds of exoplanets. (The same issue has a dramatic fold-out visual atlas of extrasolar planets, from that era.)
Naeye, R. òÀÜPlanetary Harmony: Resonances are a Key to Deciphering How Planetary Systems Form and EvolveòÀÝ In Sky & Telescope, Jan. 2005, p. 44. On theory and observations of other star systems with more than one planet.
Seager, S. òÀÜThe Hunt for Super-EarthsòÀÝ in Sky & Telescope, Oct. 2010, p. 30. The search for planets that are up to 10 times the mass of Earth and what they can teach us.
Seager, S. òÀÜAlien Earths from A to ZòÀÝ in Sky & Telescope, Jan. 2008, p. 22. How we learn what planets around other stars are made of and the range of possible planets we might expect.
Seager, S. òÀÜUnveiling Distant WorldsòÀÝ in Sky & Telescope, Feb. 2006, p. 28. Early introduction to the types of planets we found first and the methods astronomers used.
This artistòÀÙs conception shows a planet orbiting a neutron star. Purple streaks of radiation (chargedparticles) appear to interact with the planet, causing green aurorae to encircle its pole. The illustration also depicts the systemòÀÙs two other planets in the distance. (Credit: NASA/JPL-Caltech/R. Hurt)
Articles about Specific Techniques or Worlds
Boss, A. òÀÜHow Do You Make a Giant Exoplanet?òÀÝ in Astronomy, Oct. 2006, p. 38. Theories to explain the jovian planets we see out there, and what observations will help us decide among them.
Cooper, K. òÀÜPlanet Found Tugging on Transits.òÀÝ Astronomy Now. July 2010. Explains new technique used to find smaller yet-unseen planets in multi-planet transiting systems. http://www.astronomynow.com/news/n1007/09exo/
Croswell, K. òÀÜPlanetary PeculiaritiesòÀÝ in Sky & Telescope, Sep. 2008, p. 26. Brief piece on some unusual planetary discoveries around other stars.
Currie, T. & Grady, C. òÀÜPictures of a Baby Solar SystemòÀÝ in Sky & Telescope, Aug. 2012, p. 20. On LkCa15, where a dusty disk around a young star shows evidence of newly forming planets.
James, C. R. òÀÜThe Kepler SpacecraftòÀÙs Search for Other WorldsòÀÝ in Astronomy, Nov. 2010, p. 22. On the mission and the very earliest discoveries.
Jayawardhana, R. òÀÜAre Super-sized Earths the New Frontier?òÀÝ in Astronomy, Nov. 2008, p. 26. On first discoveries of planets with masses comparable to EarthòÀÙs.
Kipping, D. òÀÜSearching for Exoplanet MoonsòÀÝ in Sky & Telescope, Jul. 2009, p. 30. How future observations might reveal the presence of large moons around planets out there.
Kuchner, M. & Stark, C. òÀÜHow to Find Planets Hidden by DustòÀÝ in Astronomy, Aug. 2010, p. 24. Computer models of dusty disks & how to find planets in them.
Light curve of planet Kepler-10b transiting in front of its parent star. (Credit: Natalie Batalha)
Naeye, R. òÀÜAmateur ExoplanetsòÀÝ in Sky & Telescope, Dec. 2009, p. 22. On contributions amateur astronomers can make and are making to the search for such planets. (See also his òÀÜThe Exoplanet and the AmateursòÀÝ in the Feb. 2008 issue, p. 22.)
Naeye, R. òÀÜExoplanets Imaged at LastòÀÝ in Sky & Telescope, Mar. 2009, p. 22. On images of planets around Fomalhaut and HR 8799.
Tingley, B. òÀÜThe First Earth-Sized ExoplanetòÀÝ in Sky & Telescope, May 2009, p. 30. On CoRot-Exo-7b, a planet with somewhere between 2 and 11 Earth masses.
Villard, R. òÀÜHunting for Earthlike PlanetsòÀÝ in Astronomy, Apr. 2011, p. 28. How we expect to find and characterize super-Earth (planets somewhat bigger than ours) using new instruments and techniques that could shows us what their atmospheres are made of.
Villard, R. òÀÜHow Dying Stars Can Bring New Planets to LifeòÀÝ in Astronomy, July 2009, p. 22. On how planets form around white dwarfs and neutron stars.
Villard, R. òÀÜDoes Life Exist on this Exoplanet?òÀÝ in Astronomy, Dec. 2007, p. 44. On the planet orbiting Epsilon Eridani.
Villard, R. òÀÜHubble Discovers 16 Exotic PlanetsòÀÝ in Astronomy, Jan. 2007, p. 44. On a survey for transits in a specified star field.
Zimmerman, R. òÀÜHow Astronomers Probe Weather on ExoplanetsòÀÝ in Astronomy, Feb. 2010, p. 34. Mapping atmospheres of distant worlds.
Selected Audio Files on the Web
From left: Planet hunter Geoff Marcy, Kepler mission co-investigator Natalie Batalha, and astronomer John Johnson.
NASA Sources:
Audio Files (such as interviews) by Kepler mission scientists can be found at: http://kepler.nasa.gov/multimedia/Audio/lecturesPodcastsAndInterviews/
Other Sources:
Natalie Batalha (San Jose State University & NASA Ames): òÀÜFinding the Next Earth: The Latest Results from KepleròÀÝ (Podcast from the Silicon Valley Astronomy Lecture Series, Oct 17, 2012): http://astrosociety.org/silicon-valley-astronomy-lectures/finding-the-next-earth-the-latest-results-from-kepler/
Interview with Geoff Marcy at the National Academy of Sciences (recorded in 2009): http://www.nasonline.org/news-and-multimedia/podcasts/interviews/geoffrey-marcy.html
Geoff Marcy (University of California, Berkeley): “New Worlds and Yellowstone: How Common are Habitable Planets?” (Podcast from the Silicon Valley Astronomy Lectures, March 5, 2008): http://astrosociety.org/silicon-valley-astronomy-lectures/new-worlds-and-yellowstone-how-common-are-habitable-planets/ (See also, his talk at the University of California at Berkeley, on Jan. 17, 2009: http://astro.berkeley.edu/~scroft/iya/ )
Sara Seager (MIT) talk on the òÀÜSearch for Other EarthsòÀÝ from Mar. 2009 at McMaster University is at: http://origins.mcmaster.ca/library.php?id=18
Paul Kalas (University of California, Berkeley): “Hubble Breakthrough: The First Photos of a Planet Orbiting Another Star” (Podcast of a nontechnical talk in the Silicon Valley Astronomy Lecture Series, October 7, 2009): http://astrosociety.org/silicon-valley-astronomy-lectures/hubble-breakthrough-the-first-photos-of-a-planet-orbiting-another-star/
Selected Video Files on the Web
ArtistòÀÙs conception of system KOI-961, which contains three Earth-sized planets. (Credit: NASA/ JPL-Caltech)
NASA Sources:
Discovering Planets Beyond: Contains videos, animations, and graphics describing formation, atmospheric composition, and discovery of exoplanets.
http://hubblesite.org/hubble_discoveries/discovering_planets_beyond/
Kepler Mission Video Gallery: This site collects some of the NASA videos, public talks, news conferences, and media coverage of the Kepler discoveries. Click on the menu choices at left (under the Videos heading) to get the full range of available videos. http://kepler.nasa.gov/multimedia/videos/
Scientific Visualization StudioòÀÙs animations about exoplanets: Gallery of animations about various exoplanetary systems and detections. http://svs.gsfc.nasa.gov/search/Keyword/Exo-planet.html
Transit Timing Variation Technique Animation: This animation visually explains how transit timing variations (TTV) allow scientists on the Kepler mission to confirm multiple planets in a system. http://kepler.nasa.gov/multimedia/animations/scienceconcepts/?ImageID=98
As the Kepler mission observes planets transiting their host stars, astronomers are discovering ever-smaller planets. The Kepler 37 system, depicted in the figure alongside planets in our solar system, includes a planet only slightly larger than our Moon! (Credit: NASA/ Ames/JPL-Caltech)
Other Sources:
Geoff Marcy (U. of California, Berkeley): òÀÜThe Search for Earth-like Planets and Intelligent Life in the UniverseòÀÝ òÀÓ video of a non-technical talk at the SETI Institute, with a summary of Kepler results and general trends (Sept. 2011) [1 hr. 34 min.]: http://www.youtube.com/watch?v=jLNO5nXZoUI
An earlier version of this talk for a public audience in Berkeley (May 2011) called òÀÜDiscovery of the First Earth-Size Planets and Prospects for Life in the UniverseòÀÝ [1 hr. 23 min video]: http://vimeo.com/24390279
Sara Seager (MIT): òÀÜExoplanets and the Search for Habitable WorldsòÀÝ òÀÓ video of a public talk at the SETI Institute, with Kepler results (Dec. 2011) [1 hr. 11 min.]: http://www.youtube.com/watch?v=RLWb_T9yaDU
Natalie Batalha (San Jose State University & NASA Ames): òÀÜThe Kepler MissionòÀÝ òÀÓ a public colloquium at San Jose State (Feb. 2011) [56 min]: http://library.sjsu.edu/video/university-scholar-series-natalie-batalha
òÀÜAre We Alone: An Evening Dialogue with the Kepler Mission LeadersòÀÝ òÀÓ A non-technical panel discussion on Kepler results and ideas about planet formation with Bill Borucki, Natalie Batalha, and Gibor Basri at the Lawrence Hall of Science at the University of California, Berkeley (June 30, 2011) [2 hrs. 7 min.]: http://www.youtube.com/watch?v=O7ItAXfl0Lw
John Johnson of Caltech announces the most compact system of three roughly Earth-sized planets yet discovered at a press conference January 2012: http://www.youtube.com/watch?v=OAR2FmX8Lno&list=UUw9OIuMouGnEld3uDHkwYwQ&index=2&feature=plcp
Natalie Batalha (San Jose State University & NASA Ames): òÀÜFinding the Next Earth: The Latest Results from KepleròÀÝ òÀÓ video of a public talk in the Silicon Valley Astronomy Lecture Series (Oct 17, 2012) [1 hr. 29 min]: http://www.youtube.com/watch?v=ZbijeR_AALo
An interview with Geoff Marcy & Debra Fischer for the PBS series Quest (Apr. 2012) [11 min]: http://blogs.kqed.org/newsfix/2012/04/16/video-planet-hunter-geoff-marcy-on-the-odds-of-finding-extraterrestrial-life/
Josh Carter: òÀÜStrange Planetary VistasòÀÝ òÀÓ a public night talk at the Center for Astrophysics at Harvard, with a introduction to exoplanets for non-specialists (Dec. 13, 2012) [46 min]: http://www.youtube.com/watch?v=_8ww9eLRSCg
David Charbonneau: òÀÜThe Last Generation of Lonely AstronomersòÀÝ òÀÓ the 2012 Sackler Prize lecture, explaining the development of the study of exoplanets (June 2012) [26 min]: https://www.youtube.com/watch?v=P8F-n2wSvE4
Cartoon by PhD Comics’ Jorge Cham produced in partnership with the Johnson Exolab at Caltech: http://www.phdcomics.com/comics.php?f=1584
Educational Resources, Outreach Materials, Citizen Science
A group of amateur astronomers host a star party, allowing families with children the opportunity to look through telescopes and learn more about the sky. (Credit: Lake County Astronomical Society)
NASA Sources:
ò×Ê Activities from the Night Sky Network: How Do We Find Planets Around Other Stars? (a demonstration activity from the JPL/ASP Night Sky Network): http://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=59; Where are the Distant Worlds (an activity to map stars that have planets from the Night Sky Network): http://nightsky.jpl.nasa.gov/download-view.cfm?Doc_ID=320
ò×Ê Activities from the Kepler Mission: http://kepler.nasa.gov/education/activities/ Under the òÀÜeducationòÀÝ tab (http://kepler.nasa.gov/education/) there are several lessons (see especially òÀÜTransit TracksòÀÝ), free star wheels (planispheres) with exoplanets marked, simulations (see: Kepler Exoplanet Transit Hunt), instructions for building a Lego orrery and sources for a commercial orrery developed by the Kepler team, and a large collection of presentations (PowerPoint). The Kepler planet candidates can be explored at http://planetquest.jpl.nasa.gov/kepler
ò×Ê Space Math at NASA offers a variety of mathematics problems based upon Kepler discoveries. Look for Kepler Mission at http://spacemath.gsfc.nasa.gov/mission.html
Other Sources:
òÀÜMotion of Extrasolar PlanetsòÀÝ Lecture-Tutorial in Lecture-Tutorials for Introductory Astronomy, 3rd ed. by Prather, E., et al. (2012, Pearson). Part of a collection of 44 learning activities.
Nebraska Astronomy Applet Project Extrasolar Planets Lab: http://astro.unl.edu/naap/esp/esp.html
ò×Ê A Case of the Wobbles: Finding Extrasolar Planets (from the NASA/Montana State CERES Project): http://btc.montana.edu/ceres/html/Wobble/Wobbles.htm
McConnell, N., et al. òÀÜA College-Level, Inquiry-Based Laboratory Activity on Transiting PlanetsòÀÝ (an article describing and evaluating a lab for non-science majors): http://arxiv.org/pdf/1009.3940v2.pdf
Citizen Science
PlanetHunters.org is a citizen science project, with background information pages, where participants look at Kepler data to discover transits. It was developed by the Zooniverse team, and is led by Debra Fischer. http://www.planethunters.org
Apps and Books for Tablets and SmartPhones
*prices quoted are as of March 11, 2013
Screenshot of Exoplanet application for iPhone. The screen shows the light curve transit profile of Kepler-35 (AB) b, its size relative to other planets, and its orbit relative to our Solar system.
Other Sources:
Exoplanet: http://itunes.apple.com/us/app/exoplanet/id327702034?mt=8 (allows you to browse through a regularly updated visual catalog of exoplanets that have been found so far), Free!
Journey to the Exoplanets: http://itunes.apple.com/us/app/journey-to-the-exoplanets/id463532472?mt=8 (book produced by the staff of Scientific American, with input from scientists and space artists, this gives background information and visual tours of the nearer star systems with planets), $9.99
Notes
This Guide is intended to support the higher education community by making relevant NASA Science Mission Directorate E/PO materials and other resources of potential interest easier to find. NASA-supported education products have passed NASAòÀÙs Education Product Review. The selection of non-NASA materials and any opinions expressed in the Guide are those of the compiler, and do not imply endorsement by NASA or the Astrophysics Science Education and Public Outreach Forum.
Comments about the Exoplanet Resource Guide and the needs of the astrophysics higher education community can be directed to the Astrophysics Forum Liaison to the NASA Science Mission Directorate Higher Education Working Group: Greg Schultz (Astronomical Society of the Pacific), gschultz {at} astrosociety.org.
Acknowledgements
The Exoplanet Resource Guide was produced in collaboration with the NASA Astrophysics education and public outreach (E/PO) community. We also gratefully acknowledge the exoplanet researchers and Astronomy 101 instructors whose input on the needs of the higher education community and available resources helped shape this Guide.
Contributing NASA Astrophysics E/PO programs include: Astronomy Picture of the Day, the Hubble Space Telescope, the NASA Goddard Astrophysics Science Division, the Kepler Mission, the Night Sky Network, PlanetQuest, and the University of Arizona / JPL Exoplanet Exploration Program Center for Astronomy Education.
The Astrophysics Forum is supported by NASAòÀÙs Science Mission Directorate under Cooperative Agreement NNX09AQ11A to the Space Telescope Science Institute, Astronomical Society of the Pacific, Adler Planetarium and Astronomy Museum, and Johns Hopkins University. Contributing Team Members: Higher Education Liaison, Greg Schultz (Astronomical Society of the Pacific); NASA Content Additions, Mangala Sharma and Bonnie Meinke (Space Telescope Science Institute); Image Caption Support, Bonnie Meinke (Space Telescope Science Institute); Graphic Design: Pam Jeffries (Space Telescope Science Institute).
