Page Content (OCR)
References 405 54. Leonard David, “Homeland Defense for Earth,” Aerospace America, August 2004, 41-44; Steel, 7; “Two Telescopes Join Hunt for ET,” Vol. 440 (13 April 2006), 853. 55. Alan MacRobert, “Asteroid 2004MN4: A Really Near Miss,” Sky and Tele- scope, May 2005, 16-17. Former astronaut Rusty Schweikart provided a useful overview in “We Must Decide to Do It! The Saga of Asteroid 2004 MN4,” The Planetary Report, July-August 2005, 14-18. 56. Bova, 81. 57. Dick and Strick, 126; Ekers, et al., 287; Christopher F. Chyba, “Life Beyond Mars,” Nature, Vol. 382 (15 August 1996), 576-577; Steel, 103. 58. Robert S. Dixon, “What Caused the Dinosaurs Extinction?” Cosmic Search, Vol. 2, Number 4 (Year End 1980), 14; Luann Becker, “Repeated Blows,” Scientific American, March 2002, 76-83. 59. Joseph A. Burns, “Double Trouble,” Nature, Vol. 427 (5 February 2004), 494-495; Roald Tagle and Philippe Claeys, “Comet or Asteroid Shower in the Late Eocene?” Science, Vol. 305 (23 July 2004), 492. 60. Sagan, Pale Blue Dot, 327; Clarke, Greetings, 508; Chyba, “Life Beyond Mars.” 61. Fred Hoyle, The Black Cloud, New York, Penguin, 1960 (originally published by Heinemann in 1957); David H. Clark, “Extraterrestrial Climate Threats,” Astronomy, August 1980, 66-71; “Our Galaxy’s Deadly Spiral Arms,” Sky and Telescope, July 1998, 20; John Noble Wilford, “Sun’s Cruise Through Space is About to Hit Bumpy Patch,” The New York Times, 18 June 1996. The quotation is from “50, 100, and 150 Years Ago,” Scientific American, February 2006, 16. 62. Nigel Henbest and Heather Couper, The Guide to the Galaxy, Cambridge, Cambridge University Press, 1994, 93-94. 63. Clark, “Extraterrestrial Climate Threats;” Walter Alvarez, 58, 74; Sagan, Cosmos, 235; John Noble Wilford, “Heavens Send Earth An Enormous Surge of Stellar Radiation,” The New York Times, 30 September 1998. 64. See Robert Irion, “A Very Good Year for Explosions,” Science, Vol. 311 (6 January 2006), 30-32, and the cluster of reports by E. Berger, et al., N.R. Tanvir, et al., and S.D. Barthelmy, et al., Nature, Vol. 438 (15 December 2005), 988-996. 65. Peter J.T. Leonard and Jerry T. Bonnell, “Gamma-Ray Bursts of Doom,” Sky and Telescope, February 1998, 28-34. 66. Neil Gehrels, et al., “The Brightest Explosions in the Universe,” Scientific American, December 2002, 85-91; Malcolm W. Browne, “Astronomers Detect Immense Explosion 2d Only to Big Bang,” The New York Times, 7 May 1998. S. Yu. Sazonoy, et al. reported that, in the brightest gamma-ray bursters, the gamma-rays are so highly collimated that these events can be seen across the observable universe. “An Apparently Normal Gamma Ray Burst with an Unusually Low Luminosity,” Nature, Vol. 430 (5 August 2004), 647. 67. Leonard and Bonnell, “Gamma-Ray Bursts;” Clark and Clark, 218. 68. In Allen Tough, editor, When SETI Succeeds: The Impact of High-Informa- tion Contact, Foundation for the Future, 2000, 105. 69. Milan M. Cirkovic, “Permanence—An Adaptationist Solution to Fermi’s Paradox,” JBIS, Vol. 58 (2005), 62-70; Milan M. Cirkovic, “Earths: Rare in