During 1979, an attempt to discover evidence of discrete objects (such as interstellar probes) in stable orbits about L4 and L5 was made by Robert A Freitas Junior and Francisco Valdes by studying 90 astronomical photographical plates.
Web Resources
{text}
Book References
For discussion of the L4/L5 observations see the following:
Year |
Discussion by:
|
No. of Pages |
Ashpole, Edward in his “The Search for Extraterrestrial Intelligence“ (1989) (available on Amazon USA and on Amazon UK) at pages 133-135 (in Chapter 8) of the Blandford softcover edition. |
3 |
|
Ashpole, Edward in his “Where is Everybody?” (1997) (available on Amazon USA and on Amazon UK) at pages 139-141 (in Chapter 2) of the Sigma Press softcover edition. |
3 |
|
Benford, Gregory in “Are We Alone in the Cosmos” (1999) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 195 (in Chapter 4) of the ibooks softcover edition. |
1 |
|
Benford, Gregory in “First Contact” (1990) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 172 (in Chapter 4) of the NAL Books hardback edition, at page 220 of the Headline paperback edition. |
1 |
|
Darling, David in his “The Extraterrestrial Encyclopedia” (2000) (available on Amazon USA and on Amazon UK) at page 379 (in the table entitled “SETI Observing Programs: 1960 to the Present”) of the Three Rivers softcover edition. |
1 |
|
Freitas, Robert And Valdes, Francisco in their paper “A Search for Natural or Artificial Objects Located at the Earth-Moon Libration Points”, Icarus, Volume 42 (1980), pages 442-447. Text of draft of paper available online at: http://www.rfreitas.com/Astro/SearchIcarus1980.htm |
6 |
|
Freitas, Robert in various later papers, including “The Search for ExtraTerrestrial Artifacts (SETA)”, Journal of the British Interplanetary Society, Volume 36 (1983), pages 501-506. This article offered the “Artifact Hypothesis” that “A technologically advanced extraterrestrial civilisation has undertaken a long-term programme of' interstellar exploration via transmission of material artefacts”. It also suggested, if the Artifact Hypothesis is correct, that “some evidence of this extraterrestrial exploratory activity should be apparent within the confines of the Solar System”.Available online at: http://www.rfreitas.com/Astro/SETAJBISNov1983.htm http://www.setv.org/online_mss/seta83.html |
6 |
|
Papagiannis, Michael in “Are We Alone in the Cosmos” (1999) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 212 (in Chapter 5) of the ibooks softcover edition. |
1 |
|
Papagiannis, Michael in “First Contact” (1990) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 187 (in Chapter 5) of the NAL Books hardback edition, at page 238 of the Headline paperback edition. |
1 |
|
SETI Institute’s SETI Science and Technology Working Group (“the SSTWG”) in “SETI 2020 : A Roadmap for the Search for Extraterrestrial Intelligence” (2002) (edited by Elkers, Ronald D and Cullers, Kent D and Billingham, John and Scheffer, Louis K) (available on Amazon USA and on Amazon UK) at page 31 (in Chapter 1) of the SETI Press softcover edition. |
1 |
|
Tarter, Jill in “Extraterrestrials: Science and alien intelligence” (1985) (edited by Edward Regis) (available on Amazon USA and on Amazon UK) at page 179 (in Part 5) of the Cambridge University Press softcover edition. Also included as Reference |
1 |
|
Tarter, Jill in “Extraterrestrials: Where are they?” (1982) (edited by Michael Hart and Ben Zuckerman) (available on Amazon USA and on Amazon UK) at page 10 (in Chapter 2) of the Cambridge softcover second edition. |
1 |
|
Tarter, Jill in “SETI 2020 : A Roadmap for the Search for Extraterrestrial Intelligence” (2002) (edited by Elkers, Ronald D and Cullers, Kent D and Billingham, John and Scheffer, Louis K) (available on Amazon USA and on Amazon UK) at pages 391, 396 (in Appendix L, entitled “Archive of SETI Searches”) of the SETI Press softcover edition. |
2 |
|
Webb, Stephen in his “Where is Everybody?: Fifty Solutions to the Fermi Paradox” (2002) (available on Amazon USA and on Amazon UK) at page 37 (in Chapter 3) of the Copernicus hardback edition. |
1 |
Other Material