• First time determination of Chandler Wobble (CW) of a solar system body other than the Earth
→CW is a rotation normal mode (describes a rotational motion of the mantle)
→continuously excited by the atmosphere (most likely mechanism)
→decay time between 7-63 years (Earth 28-299 years)
→amplitude on surface ~10 cm, period=206.9d, and Q
CW=40-350 (Earth: 433.d, Q
CW=74-789)
• Updated precession rate
→MOI=0.36340±0.00006 (2016: MOI=0.3638±0.0001) (RISE paper MOI=0.3637±0.0001)
• Updated value of semi-diurnal solar tidal Love number
slightly larger than 2016 value mainly because of updated atmospheric correction
→k
2=0.174±0.008 (2016: k
2=0.169±0.006)
Consequences of updated geodesy data on interior structure models
This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as doi:
10.1029/2020GL090568
©2020 American Geophysical Union. All rights reserved.
Konopliv Alex (Orcid ID: 0000-0001-8669-1866) Park Ryan S. (Orcid ID: 0000-0001-9896-4585) Rivoldini Attilio (Orcid ID: 0000-0002-8626-9283) Baland Rose-Marie (Orcid ID: 0000-0002-5907-0033) Le Maistre Sébastien (Orcid ID: 0000-0002-9524-9479) Van Hoolst Tim (Orcid ID: 0000-0002-9820-8584)
Detection of the Chandler Wobble of Mars from Orbiting Spacecraft
Alex. S. Konopliv1, Ryan S. Park1, Attilio Rivoldini2, Rose-Marie Baland2, Sebastien Le Maistre2, Tim Van Hoolst2, Marie Yseboodt2, Veronique Dehant2
1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
2Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels, Belgium
Corresponding author: Alex Konopliv (Alex.Konopliv@jpl.nasa.gov)
Key Points:
For the first time, the Chandler wobble has been detected for a solar system body other than the Earth
The Chandler wobble is visible in the tracking data from two Mars orbiting spacecraft The Chandler wobble significantly improves our understanding of the long period
behavior of the mantle rheology
doi: 10.1029/2020GL090568
Consequences of updated geodesy data on interior structure models
EH LF MM TA YO
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Chandler Wobble and rheology Effect of k2 on core radius Effect of MOI and k
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Cold Hot
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2016• core radius 1750-1880km
slightly larger core radius than with 2016 value
• MOI Taylor composition only possible for hot mantles and thick crusts
• MOI and k
2favor thick crust for (TAY, LF, EH45) compositions except
Yoshizaki (YO)
Crust thickness-density M.W. 2020