Astronomy:Airy-0
  Airy-0 Crater from MRO; also, from A to C, Mariner 9, Viking 1 and Mars Global Surveyor (Airy-0 is the larger crater in top center of each frame). | |
| Planet | Mars |
|---|---|
| Region | Inside Airy Crater |
| Coordinates | [ ⚑ ] : 5°06′S 0°00′E / 5.1°S 0°E |
| Diameter | 0.5 kilometres (0.31 mi) |
Airy-0 is a crater inside the larger Airy Crater on Mars, whose location defined the position of the prime meridian of that planet. It is about 0.5 km (0.3 mile) across and lies within the dark region Sinus Meridiani, one of the early albedo features to be identified on Mars. In 2018, the IAU Working Group on Cartographic Coordinates and Rotational Elements recommended setting the longitude of the Viking 1 lander (47.95137° west) as the reference line.[lower-alpha 1] This definition maintains the position of the center of Airy-0 at 0° longitude, within the tolerance of current cartographic uncertainties.[1]
Merton Davies tied this crater into an extensive geodetic control network of the planet Mars based on Mariner 9 and earlier photographs.[2][3] The Mariner 9 Geodesy/Cartography Group proposed that the prime meridian of Mars be defined by the center of Airy-0, which was selected by Harold Masursky, Gerard de Vaucouleurs, and Merton Davies at a Group meeting on 14 August 1972.[4]
It was named in honor of the British Astronomer Royal Sir George Biddell Airy (1801–1892), who in 1850 built the transit circle telescope at Greenwich. The location of that telescope was subsequently chosen to define the location of Earth's prime meridian.
Notes
- ↑ In other words, the Martian Prime Meridian (0° longitude) is defined to be 47.95137° east of the Viking 1 lander site's meridian. The effect of the decision was to make more precise the location of the prime meridian within the 500 meter span of Airy-0.
References
- ↑ Archinal, B.A.Expression error: Unrecognized word "et". (2018), "Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015", Celestial Mechanics and Dynamical Astronomy 130 (22): 22, doi:10.1007/s10569-017-9805-5, Bibcode: 2018CeMDA.130...22A, "The origin of the longitude system for Mars is now defined by assigning a longitude of 47.95137° west to the Viking 1 lander.... The longitude uncertainty within which landed resources can be determined by radiometric tracking is now ... significantly smaller than the uncertainty of determining the center of the ~500 m diameter Airy-0, the time has come to transition the orientation of the longitude system from being based on Airy-0 to the much smaller Viking 1 lander, for which there are extensive radiometric tracking data."
- ↑ "The Martian Prime Meridian -- Longitude "Zero"". Malin Space Science Systems. 31 January 2001. https://mars.jpl.nasa.gov/mgs/msss/camera/images/01_31_01_releases/airy0/.
- ↑ Morton, Oliver (2002). Mapping Mars: Science, Imagination, and the Birth of a World. New York: Picador USA. pp. 22–23. ISBN 0-312-24551-3. https://archive.org/details/mappingmarsscien00mort_0.
- ↑ de Vaucouleurs, Gerard; Davies, Merton E.; Sturms, Francis M. Jr. (1973), "Mariner 9 Areographic Coordinate System", Journal of Geophysical Research 78 (20): 4395–4404, doi:10.1029/JB078i020p04395, Bibcode: 1973JGR....78.4395D
External links
- View of Airy-0 at Google Mars
- T. C. Duxbury; P. Christensen; D. E. Smith; G. A. Neumann; R. L. Kirk; M. A. Caplinger; A. A. Albee; N. V. Seregina et al. (December 2014). "The location of Airy-0, the Mars prime meridian reference, from stereo photogrammetric processing of THEMIS IR imaging and digital elevation data". Journal of Geophysical Research: Planets 119 (12): 2471–2486. doi:10.1002/2014JE004678. Bibcode: 2014JGRE..119.2471D.
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