Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes (2019)

Chapter: Appendix C: Advantages and Disadvantages of Ground- and Space-Based Options for Infrared and Visible Observations of Near Earth Objects

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Suggested Citation: "Appendix C: Advantages and Disadvantages of Ground- and Space-Based Options for Infrared and Visible Observations of Near Earth Objects." National Academies of Sciences, Engineering, and Medicine. 2019. Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes. Washington, DC: The National Academies Press. doi: 10.17226/25476.
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C

Advantages and Disadvantages of Ground- and Space-Based Options for Infrared and Visible Observations of Near Earth Objects

System Advantages Disadvantages
Visible/Radar Systems—Ground- and Space-Based
Ground-Based Visible Survey (e.g., PanSTARRS, CSS, LSST)
  • Accurate orbits
  • Preliminary H (required for size estimate once albedo is determined, or vice versa); may provide data on rotation rate and shape
  • Relatively low cost (LSST already under construction)
  • Size estimation based on assumed albedo uncertain
  • Will take decades to even approach 90% completeness—cannot meet the George E. Brown, Jr. Near-Earth Object Survey Act limit
Ground-Based Visible Characterization Using Photometry and Spectroscopy
  • Can provide improved H value, taxonomy, mineralogy, and tighter constraints on albedo; light curves provide rotation rate, constrain shape, may provide evidence of satellite
  • Field of view impractical for searches; effective only for characterizing known objects
Ground-Based Radar Characterization (e.g., Goldstone, Arecibo)
  • Can provide sizes of known objects if they pass sufficiently close to Earth, therefore can provide albedos given H
  • Can dramatically increase the accuracy of orbits of known objects
  • May provide rotation rate, shape, high-resolution images, confirmation of satellite
  • Arecibo, Goldstone already exist; maintenance costs are known; each also has non-NEO users
  • Impractical for searches; effective only for characterizing known objects
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Suggested Citation: "Appendix C: Advantages and Disadvantages of Ground- and Space-Based Options for Infrared and Visible Observations of Near Earth Objects." National Academies of Sciences, Engineering, and Medicine. 2019. Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes. Washington, DC: The National Academies Press. doi: 10.17226/25476.
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System Advantages Disadvantages
Space-Based Visible Survey (e.g., 0.5 m at L1)
  • Accurate orbits
  • Preliminary H
  • Some characterization depending on instrumentation
  • Size uncertainty similar to that of ground-based surveys
  • Will take decades to even approach 90% completeness—cannot meet the George E. Brown, Jr. Near-Earth Object Survey Act limit
  • Tradeoff between aperture size, cost, and contribution beyond LSST
  • Potentially costly at approximately $550 million plus launch
  • Options to reduce cost below that of Discovery missions exist but mean longer time to achieve completion
Space-Based Visible Survey (SmallSat platform)
  • Lower cost than other options — approximately $40 million per satellite
  • Insufficient sensitivity to reach George E. Brown, Jr. Near-Earth Object Survey Act criterion
  • Software for orbit determination does not exist but is under development
Infrared Systems—Ground and Space Based
Space-Based Infrared Survey (50 cm at L1)
  • Accurate sizes
  • Tight constraints on albedo, given H
  • Able to complete survey roughly 10 years after launch
  • Potentially expensive at $550 million plus launch
Ground-Based Characterization—Mid-Infrared (e.g., Keck, LBT, Gemini)
  • Accurate sizes
  • Tight constraints on albedo, given H
  • Small field of view and low, unreliable sensitivity due to Earth’s atmosphere make searches impractical
  • Can measure rotation rate, etc., but no benefit over visible wavelength measurements
Air-Based Characterization—Aircraft, Mid-Infrared (5-35 μm) (e.g., SOFIA)
  • Accurate sizes
  • Tight constraints on albedo, given H
  • Suffers much less from atmospheric effects than ground-based infrared
  • Small field of view makes searches impractical
  • Can measure rotation rate, etc., but no benefit over visible wavelength measurements
  • Less flexible and more costly than ground-based infrared

NOTE: CSS, Catalina Sky Survey; LBT, Large Binocular Telescope; LSST, Large Synoptic Survey Telescope; NEO, near Earth object; Pan-STARRS, Panoramic Survey Telescope and Rapid Response System; SOFIA, Stratospheric Observatory for Infrared Astronomy.

Page 54 Cite Bookmark
Suggested Citation: "Appendix C: Advantages and Disadvantages of Ground- and Space-Based Options for Infrared and Visible Observations of Near Earth Objects." National Academies of Sciences, Engineering, and Medicine. 2019. Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes. Washington, DC: The National Academies Press. doi: 10.17226/25476.
Save
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Page 54
Page 55 Cite Bookmark
Suggested Citation: "Appendix C: Advantages and Disadvantages of Ground- and Space-Based Options for Infrared and Visible Observations of Near Earth Objects." National Academies of Sciences, Engineering, and Medicine. 2019. Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes. Washington, DC: The National Academies Press. doi: 10.17226/25476.
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