1. Daniel Clery, “Planet Hunter Nears its End.” Science, Vol. 362, p. 275.
2. “We’ve learned that we really don’t know what we’re talking about with respect to exoplanets: how they form, what their distributions are, anything ! ” Gibor Basri, “Is Anybody Out There?” Discover, November 2010, p. 49.
3. “The discovery of thousands of star systems wildly different from our own has demolished ideas about how planets form. Astronomers are searching for a whole new theory.” Ann Finkbeiner, “Planets in Chaos,” Nature, Vol. 511, 3 July 2014, p. 22.
u “With so little in common with the familiar Solar System planets, these newcomers spell the end for established theories of planet formation.” Dan Falk, “Planet Formation,” Nature, Vol. 422, 17 April 2003, p. ix.
u “All planetary systems were supposed to look like ours ... . The planets we’re finding are in the wrong places! And their orbits are unlike anything anyone predicted. Now, that’s a warning. That tells you we don’t know how to predict what’s out there.” William Borucki, as quoted by Tim Folger, “The Planet Boom,” Discover, May 2011, p. 39.
u “Moreover, the predictions made by theoretical [evolutionary] models of solar system formation when confronted with observations of exoplanets, fail rather spectacularly.” Frederic A. Rasio, “A Black Widow’s Best Friend?” Science, Vol. 333, 23 September 2011, p. 1712.
4. “Most of the worlds we have found seem unlikely to support life [because of temperatures].” Adam Frank, “How Nature Builds a Planet,” Discover, Vol. 26, July 2005, p. 30.
5. “Dangers of Publication by Press Conference,” Nature, Vol. 393, 4 June 1998, p. 397.
6. Ron Cowen, “The Planet That Isn’t,” Science News, Vol. 157, 22 April 2000, p. 271.
u Susan Terebey et al., “The Spectrum of TMR-1C Is Consistent with a Background Star,” The Astronomical Journal, Vol. 19, May 2000, pp. 2341–2348.
7. L. F. Miranda et al., “Water-Maser Emission from a Planetary Nebula with a Magnetic Torus,” Nature, Vol. 414, 15 November 2001, pp. 284–286.
8. “Finally, it is possible that regardless of how many and where planets form, the dynamical perturbations experienced over the history of the cluster would be too disruptive to allow the survival of any planets ...” Steinn Sigurdsson et al., “A Young White Dwarf Companion to Pulsar B1620-26: Evidence for Early Planet Formation,” Science, Vol. 301, 11 July 2003, p. 195.
u “The discovery of a giant planet amid a cluster of primitive stars is challenging one of astronomers’ pet notions. ... [The planet would have to have been] born billions of years before most astrophysicists thought the universe had spawned the raw materials needed to make them.” Robert Irion, “Ancient Planet Turns Back the Clock,” Science, Vol. 301, 11 July 2003, p. 151.
9. Ron Cowen, “One Star Better Than Two?” Science News, Vol. 169, 21 January 2006, p. 46.
u “For a long time people didn’t believe there could be planets orbiting a pair of stars [because planets would not be able to evolve].” William Borucki, as quoted by Andrew Grant, “William Borucki: Planet Hunter,” Discover, December 2012, p. 49.
10. “Planetesimal formation around an eccentric binary is a theoretical challenge, because of the large collision velocities of particles that are stirred by the stellar binary.” Laurance R. Doyle et al., “Kepler-16: A Transiting Circumbinary Planet,” Science, Vol. 333, 16 September 2011, p. 1606.
11. “... close binary stars can host complete planetary systems.” Jerome A. Orosz et al., “Kepler-47: A Transiting Circumbinary Multiplanet System,” Science, Vol. 337, 21 September 2012, p. 1511.
u “It’s hard enough to imagine how you get one planet in the binary; now we have two.” William Welsh, as quoted by Nadia Drake, “Exoplanet Pair Orbits Twin Suns,” Science News, Vol. 182, 6 October 2012, p. 12.
12. Maciej Konacki, “An Extrasolar Giant Planet in a Close Triple-Star System,” Nature, Vol. 436, 14 July 2005, pp. 230–233.
u “The discovery by Maciej Konacki of a giant planet in a system where the gravitational pull of a second star would disturb the planet’s putative nursery will now place severe constraints on such [evolutionary] theories.” Artie P. Hatzes and Günther Wuchterl, “Giant Planet Seeks Nursery Place,” Nature, Vol. 436, 14 July 2005, p. 182.
u “In July [2005] Caltech planetary scientist Maciej Konacki turned up a world with three suns in the constellation Cygnus. Finding that a planet could exist in a multiple-star system counter to theoretical expectations, ‘will put our theories of planet formation to a strict test,’ says Konacki.” Jack Kelley, “Hunt for Another Earth Broadens,” Discover, Vol. 27, January 2006, p. 26.
13. “Planets have been discovered in a variety of binary configurations. For example, about seven transiting circumbinary planets have been discovered in Kepler satellite data and two jovian planets have been found in binary systems using RV [radial velocity techniques].” A. Gould et al., “A Terrestrial Planet in a ~1-AU Orbit Around One Member of a ~15-AU Binary,” Science, Vol. 345, 4 July 2014, p. 49.
14. Instead of gaining mass, as any evolving planet must do, one extrasolar planet is so close to its star that it is losing at least 10,000 metric tons of hydrogen a second. The rate of loss may be several orders of magnitude greater. [See A. Vidal-Madjar et al., “An Extended Upper Atmosphere Around the Extrasolar Planet HD209458b,” Nature, Vol. 422, 13 March 2003, pp. 143–146.]
15. “More of these ‘hot Jupiters’ (orbiting within a tenth of the Earth-Sun distance) were soon found, making it clear that the principles underlying the formation of planetary systems needed some revision.” Gibor Basri, “Too Close for Comfort,” Nature, Vol. 430, 1 July 2004, p. 24.
16. Vanessa Bailey et al., “HD 106906 b: A Planetary-Mass Companion Outside a Massive Debris Disk,” The Astrophysical Journal Letters, Vol. 780, 1 January 2014, p. L4.
17. “Cameron and colleagues recently studied 27 exoplanets and found that one-third had highly tilted orbits, including at least four that orbited backward.” Stephen Ornes, “Wrong-Way Worlds,” Discover, November 2010, p. 17.
18. M. R. Zapatero Osorio et al., “Discovery of Young, Isolated Planetary Mass Objects in the s Orionis Star Cluster,” Science, Vol. 290, 6 October 2000, pp. 103–107.
19. “Five of the six planets are packed into orbits smaller than that of Mercury, their paths almost perfectly aligned in the same plane. Astronomers are at a loss to explain how all the planets managed this configuration without crashing into each other.” Andrew Grant, “The Planet Boom,” Discover, May 2011, p. 34.
u “ ‘The Kepler-11 planetary system is amazing,’ said Jack Lissauer, a planetary scientist and a Kepler science team member at NASA's Ames Research Center, Moffett Field, Calif. ‘It’s amazingly compact; it’s amazingly flat; there’s an amazingly large number of big planets orbiting close to their star—we didn’t know such systems could even exist.’ ” NASA Bulletin, “NASA's Kepler Spacecraft Discovers Extraordinary New Planetary System,” 2 February 2011.
u W. F. Welsh et al., “Dual ‘Suns’ Are No Novelty,” Nature, Vol. 481, 12 January 2012, p. 147.
20. “Extrasolar planets have peculiar properties, and our understanding of how planets form, which was incomplete even before the new data became available, now looks even shakier.” Dan Falk, “Worlds Apart,” Nature, Vol. 422, 17 April 2003, p. 659.
u “ [Planets] form through processes that do not clearly fit into any of the standard theoretical models.” Frank, p. 30.
u Ron Cowen, “What Is a Planet: New Riddles beyond the Solar System?” Science News, Vol. 170, 2 December 2006, pp. 360–361.
u “The astonishing close orbits and incredibly high planetary temperatures for the so-called hot Jupiters shattered the Solar System paradigm of planet formation and was the first surprising discovery of many in exoplanetary science.” Drake Deming and Sara Seager, “Light and Shadow from Distant Worlds,” Nature, Vol. 462, 19 November 2009, p. 301.