Terrestrial Planet Finder

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Terrestrial Planet Finder - Infrared interferometer concept
Terrestrial Planet Finder - Infrared interferometer concept

The Terrestrial Planet Finder (TPF) was a plan by the National Aeronautics and Space Administration of the United States for a telescope system that would have been capable of detecting extrasolar terrestrial planets.

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[edit] History

In May 2002, NASA chose two TPF mission architecture concepts for further study and technology development. Each would use a different means to achieve the same goal—to block the light from a parent star in order to see its much smaller, dimmer planets. That technology challenge has been likened to finding a firefly near the beam of a distant searchlight. Additional goals of the mission would include characterizing the surfaces and atmospheres of newfound planets, and looking for the chemical signatures of life. In May 2004, both architectures were approved. Congressional spending limits under House Resolution 20 passed on January 31, 2007, by the United States House of Representatives and February 14 by the U.S. Senate have postponed the program indefinitely.

The two planned architectures were:

  • Infrared astronomical interferometer (TPF-I): Multiple small telescopes on a fixed structure or on separated spacecraft floating in precision formation would simulate a much larger, very powerful telescope. The interferometer would use a technique called nulling to reduce the starlight by a factor of one million, thus enabling the detection of the very dim infrared emission from the planets.
  • Visible Light Coronagraph (TPF-C): A large optical telescope, with a mirror three to four times bigger and at least 10 times more precise than the Hubble Space Telescope, would collect starlight and the very dim reflected light from the planets. The telescope would have special optics to reduce the starlight by a factor of one billion, thus enabling astronomers to detect the faint planets.

NASA and Jet Propulsion Laboratory (JPL) were to issue calls for proposals seeking input on the development and demonstration of technologies to implement the two architectures, and on scientific research relevant to planet finding. Launch of TPF-C had been anticipated to occur around 2014, and TPF-I possibly by 2020.

According to NASA's 2007 budget documentation, released on 2006-02-06,[1] the project was deferred indefinitely.[2] In June 2006, a House of Representatives subcommittee voted to provide funding for the TPF along with the long-sought mission to Europa, a moon of Jupiter that may harbor extraterrestrial life.[3] However, as of April 2007, actual funding has not materialized, and TPF remains without a launch date.[4]

The European Space Agency, ESA, is considering a similar mission, called Darwin.

[edit] Top 100 TPF target stars

Rank [5] Name Constellation Distance (ly) Spectral
type		 Known
planets
1 Alpha Centauri A Centaurus 4.3 G2V  
2 Alpha Centauri B Centaurus 4.3 K1V  
3 Tau Ceti Cetus 12 G8V  
4 Achird Cassiopeia 19 G3V  
5 Beta Hydri Hydrus 24 G2V  
6 Delta Pavonis Pavo 20 G8V  
7 Tabit Orion 26 F6V  
8 Gamma Leporis Lepus 29 F7V  
9 Epsilon Eridani Eridanus 10 K2V 1
10 Keid Eridanus 16 K1V  
11 Zeta Tucanae Tucana 28 F9V  
12 Zavijava Virgo 36 F9V  
13 Beta Comae Berenices Coma Berenices 30 G0V  
14 Gamma Pavonis Pavo 30 F6V  
15 Iota Persei Perseus 34 G0V  
16 Epsilon Indi Indus 12 K5V  
17 Gamma Serpentis Serpens 36 F6V  
18 Alsafi Draco 19 K0V  
19 Theta Persei Perseus 37 F7V  
20 61 Virginis Virgo 28 G6V  
21 Upsilon Andromedae Andromeda 44 F8V 3
22 Kappa Ceti Cetus 30 G5V  
23 Iota Piscium Pisces 47 F7V  
24 10 Tucanae Tucana 43 F9IV  
25 HD 102365 Centaurus 30 G3V  
26 Zeta Doradus Dorado 38 F7V  
27 Lambda Aurigae Auriga 41 G1IV  
28 Asellus Primus Boötes 47 F7V  
29 Psi Capricorni Capricornus 48 F5V  
30 Alchiba Corvus 48 F2V  
31 Alpha Mensae Mensa 33 G5V  
32 Sigma Boötis Boötes 50 F2V  
33 Eta Leporis Lepus 49 F1V  
34 Beta Trianguli Australis Triangulum Australe 40 F2III  
35 Xi Pegasi Pegasus 53 F7V  
36 HD 84117 Hydra 49 G0V  
37 47 Ursae Majoris Ursa Major 46 G1V 2
38 I Carinae Carina 53 F2IV  
39 Nu Phoenicis Phoenix 49 F8V  
40 111 Tauri Taurus 48 F8V  
41 61 Ursae Majoris Ursa Major 31 G8V  
42 Mu Arae Ara 50 G3IV-V 4
43 G Lupi Lupus 60 F5IV-V  
44 Phi2 Ceti Cetus 51 F7IV-V  
45 58 Ophiuchi Ophiuchus 57 F7V  
46 Tau6 Eridani Eridanus 58 F3V  
47 HD 147513 Scorpius 42 G5V 1
48 Eta Corvi Corvus 59 F2V  
49 HD 5015 Cassiopeia 61 F8V  
50 Psi5 Aurigae Auriga 54 G0V  
51 72 Herculis Hercules 47 G0V  
52 τ PsA Piscis Austrinus 61 F6V  
53 6 Ceti Cetus 62 F5V  
54 20 Leonis Minoris Leo Minor 49 G3Va  
55 HD 219134 Cassiopeia 21 K3V  
56 15 Leonis Minoris Leo Minor 60 G0.5Va  
57 Zeta1 Reticuli Reticulum 39 G2.5V  
58 58 Eridani Eridanus 43 G3V  
59 Chi Cancri Cancer 59 F6V  
60 110 Herculis Hercules 62 F6V  
61 59 Virginis Virgo 59 G0Vs  
62 18 Scorpii Scorpius 46 G1V  
63 55 Cancri Cancer 40 G8V 5
64 HD 104304 Virgo 42 G9IV  
65 51 Pegasi Pegasus 50.1 G2.5V 1
66 45 Boötis Boötes 64 F5V  
67 Omicron Aquilae Aquila 63 F8V  
68 74 Orionis Orion 64 F5IV-V  
69 Iota Horologii Horologium 51 G0V 1
70 Rijl al Awwa Virgo 61 F2III  
71 Alpha Chamaeleontis Chamaeleon 63 F5III  
72 HD 192310 Capricornus 29 K0V  
73 Pi1 Ursae Majoris Ursa Major 46 G1.5Vb  
74 Eta Crucis Crux 64 F2III  
75 HD 207129 Grus 51 G0V  
76 HD 46588 Camelopardalis 58 F8V  
77 Nu2 Lupi Lupus 48 G4V  
78 17 Cygni Cygnus 68 F7V  
79 40 Leonis Leo 69 F6IV  
80 HD 53705 Puppis 53 G3V  
81 HD 55575 Lynx 55 G0V  
82 q1 Eridani Eridanus 57 F9V 1
83 HD 65907 Carina 53 G0V  
84 12 Ophiuchi Ophiuchus 32 G0V  
85 Gamma Doradus Dorado 66 F4III  
86 HD 25457 Eridanus 63 F5V  
87 Gliese 570 Libra 19 K4Ve  
88 HD 33564 Camelopardalis 68 F6V 1
89 Kappa Reticuli Reticulum 70 F5IV-V  
90 22 Lyncis Lynx 65 F6V  
91 I Puppis Puppis 69 F0IV  
92 HD 212330 Tucana 67 G3IV  
93 HD 91324 Vela 71 F6V  
94 71 Orionis Orion 69 F6V  
95 Lambda Arae Ara 71 F3IV  
96 Psi Draconis Draco 72 F5IV-V  
97 Gliese 777 Cygnus 59 G6IV 2
98 HD 172051 Sagittarius 42 G5V  
99 HD 4391 Phoenix 49 G1V  
100 Pi Mensae Mensa 67 G1IV 1

[edit] See also

[edit] References

  1. ^ NASA budget statement. Planetary Society (2006-02-06). Retrieved on 2006-07-17.
  2. ^ NASA President's FY 2007 Budget Request
  3. ^ House subcommittee helps save our science. Planetary Society (2006-06-14). Retrieved on 2006-07-17.
  4. ^ Charles Q. Choi (2007-04-18). New Technique Will Photograph Earth-Like Planets. Space.com. Retrieved on 2007-05-02.
  5. ^ TPF C's Top Target Stars Space Telescope Science Institute

[edit] External links

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