The home page for the "New Horizons" mission, which will fly by Pluto and Charon and on to the Kuiper Belt, is at http://pluto.jhuapl.edu/

Mike Brown's page about the discovery of Eris and the most recent observations of it is at http://www.gps.caltech.edu/~mbrown/planetlila/

Background image: parting image taken by Voyager 2, PIA00143 http://photojournal.jpl.nasa.gov/catalog/PIA00143

Voyager: from NSSDC Voyager Project Information http://nssdc.gsfc.nasa.gov/planetary/voyager.html

Uranus: from NSSDC Photo Gallery: Uranus http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-uranus.html

Uranus/Earth comparison table: after "The Cambridge Photographic Guide to the Planets" by F. W. Taylor (Cambridge UP, 2001), p. 268.

Herschel: from National Air and Space Museum, Exploring the Planets: Discovering New Planets http://www.nasm.si.edu/ceps/etp/discovery/disc_planets.html

Why Uranus is blue: from "Explorations: An Introduction to Astronomy" by Thomas T. Arny, Fig. 9.18, http://www.mhhe.com/physsci/astronomy/arny/instructor/graphics/ch09/0918.html

Atmosphere and rings: picture from the Keck Telescope, from Astronomy Picture of the Day 2004 November 18 http://antwrp.gsfc.nasa.gov/apod/ap041118.html

Seasons: from Astronomy 121: The Solar System by Jim Brau http://blueox.uoregon.edu/~courses/BrauImages/Chap13/FG13_006.jpg

Side-on rings: Hubblesite release STScI-2005-33 http://hubblesite.org/newscenter/archive/releases/solar-system/uranus/2005/33/. Eclipse on Uranus: Hubblesite release STScI-2006-42 http://hubblesite.org/newscenter/archive/releases/solar-system/uranus/2006/42/

Changing view of Uranus: from Imke de Pater http://astro.berkeley.edu/~imke/Infrared/UranusAo/Uranus_darkrings.htm

Dark cloud: Hubblesite release STScI-2006-47 http://hubblesite.org/newscenter/archive/releases/2006/47/

Interior: from Views of the Solar System by Calvin J. Hamilton http://www.solarviews.com/browse/uranus/uranusint.jpg

Storms on Uranus: from Hubble Site News Release Archive, March 29 1999, "Huge Spring Storms Rouse Uranus from Winter Hibernation" http://hubblesite.org/newscenter/archive/1999/11/

Uranus' magnetic field: from Astronomy 161, The Solar System, Lect 17 http://csep10.phys.utk.edu/astr161/lect/uranus/surface.html

Rings: false colour image of a Voyager photo, from Views of the Solar System by Calvin J. Hamilton http://www.solarviews.com/cap/uranus/u-ring.htm

Moon pictures: from Views of the Solar System by Calvin J. Hamilton http://www.solarviews.com/eng/triton.htm

Montage of Uranus and moons: artist's impression based on Voyager images. From Smithsonian Institution: Exploring The Planets: Uranus http://www.hrw.com/science/si-science/physical/astronomy/ss/uranus/uran_moons.html

Uranus encounter times: from "Atlas of Uranus" by Garry Hunt and Patrick Moore (Cambridge UP, 1989), p. 53

HST image of rings and moons: from Astronomy Picture of the Day 26 November 1997 http://antwrp.gsfc.nasa.gov/apod/ap971126.html

Changing position of the poles: re-drawn from "Atlas of Uranus" by Garry Hunt and Patrick Moore (Cambridge UP, 1989), p. 30

Moon images: from Views of the Solar System by Calvin J. Hamilton http://www.solarviews.com/eng/uranus.htm

Montage of Neptune and Triton: from Views of the Solar System by Calvin J. Hamilton http://www.solarviews.com/cap/nep/trinep1.htm

Adams: from "John Couch Adams and the discovery of Neptune" by A. B. Ruth, The Eagle 1997 http://www.joh.cam.ac.uk/publications/eagle97/Eagle97-John.html

Neptune and Uranus compared: http://astsun.astro.virginia.edu/~mnc3z/astro121.html

Full disk of Neptune: Voyager image, from Views of the Solar System by Calvin J. Hamilton http://www.solarviews.com/cap/nep/neptunes.htm

Atmosphere images: from Views of the Solar System by Calvin J. Hamilton http://www.solarviews.com/cap/index/neptune.html

Time-lapse movie of Neptune's weather: from HST news release archive, "Hubble Makes Movie of Neptune's Rotation and Weather", October 24 1996, http://hubblesite.org/newscenter/archive/1996/33/

Interiors and magnetic fields: from "Planets, Stars and Galaxies" by Todd Adams, www.hep.fsu.edu/~tadams/courses/fall02/ast1002/lectures/Lecture092502.pdf

Rings: from Voyager 2 Gallery of Neptune's Ring System http://ringmaster.arc.nasa.gov/neptune/voyager/

Moons: from "Satellites of the outer planets" http://www.lpi.usra.edu/research/outerp/moons.html

Orbits of Triton and Nereid: re-drawn from "Atlas of Uranus" by Garry Hunt and Patrick Moore (Cambridge UP, 1989), p. 50

New moons of Neptune: from CfA Press Release No.: 03-03, "New Moons Found Around Neptune" http://cfa-www.harvard.edu/press/pr0303.html

Moon collision: painting by Don Davis, from http://www.universetoday.com/am/publish/pluto_3_moons.html

Binary capture of Triton: from Alessandro Morbidelli, "Interplanetary kidnap", Nature, 441, 162 (2006)

Artist's conception of Pluto and Charon: from Astronomy Picture of the Day 2001 October 18 http://antwrp.gsfc.nasa.gov/apod/ap011018.html

HST image of Pluto/Charon: from Astronomy Picture of the Day 13 February 1999 http://antwrp.gsfc.nasa.gov/apod/ap990213.html

Pluto discovery images: from Astronomy 110 by Gareth Wynn-Williams, Lecture 9: The small planetary bodies http://www.ifa.hawaii.edu/~wynnwill/110/9_small_bodies.htm

Pluto's orbit: from "The Cosmic Perspective" by Bennett, Donahue, Schneider and Voit, (Benjamin Cummings, 2000), http://dosxx.colorado.edu/Pluto/orbits.jpg

Charon's orbit: from Pluto Home by Paul McGehee, http://dosxx.colorado.edu/Pluto/pluto1.html

Mutual eclipses: from Pluto Home by Paul McGehee, http://dosxx.colorado.edu/Pluto/pluto2.html

Colour image of Pluto: from "Mapping Pluto's Surface" by Eliot Young http://www.boulder.swri.edu/~efy/PMap01/PlutoMaps/PlutoMaps.html

Pluto animation: from Hubble News Release Archive, 7 March 1996, "Hubble Reveals Surface of Pluto for First Time" http://hubblesite.org/newscenter/archive/1996/09/

Artist's impression of Pluto/Charon: Fahad Sulehria http://www.novacelestia.com/images/space_art_pluto_charon.jpg

New Horizons image and animation: from "New Horizons: NASA's Pluto-Kuiper Belt mission" http://pluto.jhuapl.edu/index.php

Eris images: Michael Brown: The discovery of 2003 UB313 Eris, the 10th planet largest known dwarf planet http://www.gps.caltech.edu/~mbrown/planetlila/

Eris orbit: Wikipedia http://en.wikipedia.org/wiki/Eris_(dwarf_planet)

Voyagers entering the solar heliopause: from " Voyager Enters Solar System's Final Frontier", http://www.nasa.gov/vision/universe/solarsystem/voyager_agu.html