| タイトル | The Gravity Field, Orientation, and Ephemeris of Mercury from MESSENGER Observations After Three Years in Orbit |
| 本文（外部サイト） | http://hdl.handle.net/2060/20150000346 |
| 著者（英） | Lemoine, Gregory; Goossens, Sander; Mazarico, Erwan M.; Solomon, Sean C.; Zuber, Maria T.; Smith, David E.; Neumann, Gregory A.; Genova, Antonio |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2014-01-01 |
| 言語 | eng |
| 内容記述 | We have analyzed three years of radio tracking data from the MESSENGER spacecraft in orbit around Mercury and determined the gravity field, planetary orientation, and ephemeris of the innermost planet. With improvements in spatial coverage, force modeling, and data weighting, we refined an earlier global gravity field both in quality and resolution, and we present here a spherical harmonic solution to degree and order 50. In this field, termed HgM005, uncertainties in low-degree coefficients are reduced by an order of magnitude relative to the earlier global field, and we obtained a preliminary value of the tidal Love number k(sub 2) of 0.451+/-0.014. We also estimated Mercury's pole position, and we obtained an obliquity value of 2.06 +/- 0.16 arcmin, in good agreement with analysis of Earth-based radar observations. From our updated rotation period (58.646146 +/- 0.000011 days) and Mercury ephemeris, we verified experimentally the planet's 3: 2 spin-orbit resonance to greater accuracy than previously possible. We present a detailed analysis of the HgM005 covariance matrix, and we describe some near-circular frozen orbits around Mercury that could be advantageous for future exploration. |
| NASA分類 | Lunar and Planetary Science and Exploration |
| レポートNO | GSFC-E-DAA-TN18499 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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