Encyclopedia of Planetary Landforms

2015 Edition
| Editors: Henrik Hargitai, Ákos Kereszturi

Radar Anomaly (Venus)

  • Erika KohlerEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-3134-3_289


A high reflectivity radar feature concentrated in the Venusian highlands.


A type of  radar feature


Strong radar signal reflected from elevations above about 2.5 km (near the equator) or 5 km (at 60°N) on Venus that becomes less pronounced at the highest elevations (Klose et al. 1992); there is also a commensurate low microwave emissivity at the same locations. The planetary average reflectivity on Venus is 0.14 ± 0.03. However, this reflectivity ranges between 0.35 ± 0.04 and 0.43 ± 0.05 in the highlands (Pettengill et al. 1988). Most of the high-altitude regions displaying anomalous reflectivity and emissivity are also very rough on centimeter to meter scales, making inference of surface properties difficult. A notable exception is the crater Cleopatra on the flank of Maxwell Montes, which has enough mirror-like surface elements that a quasi-specular echo could be measured during Magellan bistatic radar experiments in 1994.



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  1. Brackett RA, Fegley B, Arvidson RE (1995) Volatile transport on Venus and implications for surface geochemistry and geology. J Geophys Res 100:1553–1563CrossRefGoogle Scholar
  2. Campbell DB, Dyce RB, Pettengill GH (1976) New radar image of Venus. Science 193:1123–1124CrossRefGoogle Scholar
  3. Campbell BA, Campbell DB, DeVries CH (1999) Surface processes in the Venus highlands: results from analysis of Magellan and Arecibo data. J Geophys Res 104(E1):1897–1916. doi:10.1029/1998JE900022CrossRefGoogle Scholar
  4. Ford PG, Pettengill GH (1983) Venus: global surface radio emissivity. Science 220:1379–1380CrossRefGoogle Scholar
  5. Ford PG, Pettengill GH (1992) Venus topography and kilometer-scale slopes. J Geophys Res 97(E8):13103–13114CrossRefGoogle Scholar
  6. Garvin JB, Head JW, Pettengill GH, Zisk SH (1985) Venus global radar reflectivity and correlations with elevation. J Geophys Res 90:6859–6871CrossRefGoogle Scholar
  7. Klose KB, Wood JA, Hashimoto A (1992) Mineral equilibria and the high radar reflectivity of Venus mountaintops. J Geophys Res 97(E10):16,353–16,369. doi:10.1029/92JE01865CrossRefGoogle Scholar
  8. Kohler E, Gavin P, Chevrier V, Johnson N (2012) Experimental investigations into the radar anomalies on Venus. Lunar Planet Sci Conf XLIII, abstract #2749, The Woodlands, 19–23 MarGoogle Scholar
  9. Kohler E, Chevrier V, Gavin P, Johnson N (2013) Experimental stability of tellurium and its implications for the Venusian radar anomalies. Lunar Planet Sci Conf XLIV, abstract #2951, The Woodlands, 18–22 MarGoogle Scholar
  10. Pettengill GH, Ford PG (1993) Origins of the low values of radiothermal emissivity seen in some parts of Venus. Eos Trans AGU 74:189CrossRefGoogle Scholar
  11. Pettengill GH, Ford PG, Chapman BD (1988) Venus: surface electromagnetic properties. J Geophys Res 93:14,881–14,892CrossRefGoogle Scholar
  12. Pettengill GH, Ford PG, Wilt RJ (1992) Venus surface radiothermal emission as observed by Magellan. J Geophys Res 97(E8):13067–13090CrossRefGoogle Scholar
  13. Pettengill GH, Ford PG, Simpson RA (1996) Electrical properties of the Venus surface from bistatic radar observations. Science 272:1628–1631CrossRefGoogle Scholar
  14. Robinson CA, Thornhill GD, Parfitt EA (1995) Large-scale volcanic activity at Maat Mons: can this explain fluctuations in atmospheric chemistry observed by Pioneer Venus? J Geophys Res 100(E6):11,755–11,763. doi:10.1029/95JE00147CrossRefGoogle Scholar
  15. Rogers A, Ingalls R (1970) Radar mapping of Venus with interferometric resolution of the range-Doppler ambiguity. Radio Sci 5:425–433CrossRefGoogle Scholar
  16. Schaefer L, Fegley B (2004) Heavy metal frost on Venus. Icarus 168:215–219CrossRefGoogle Scholar
  17. Shepard MK, Arvidson RE, Brackett RA, Fegley BA (1994) Ferroelectric model for the highlands of Venus. Geophys Res Lett 21:469–472CrossRefGoogle Scholar
  18. Tryka KA, Muhleman DO (1992) Reflection and emission properties on Venus: alpha regio. J Geophys Res 97:13,379–13,394CrossRefGoogle Scholar
  19. Tyler GL, Simpson RA, Maurer MJ, Holmann E (1992) Scattering properties of the Venusian surface: preliminary results from Magellan. J Geophys Res 97(E8):13115–13140CrossRefGoogle Scholar

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© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Arkansas Center for Space and Planetary SciencesUniversity of ArkansasFayettevilleUSA