Solar system expansion and strong equivalence principle as seen by the NASA MESSENGER mission

Antonio Genova; Erwan Mazarico; Sander Goossens; Frank G Lemoine; Gregory A Neumann; David E Smith; Maria T Zuber

doi:10.1038/s41467-017-02558-1

Solar system expansion and strong equivalence principle as seen by the NASA MESSENGER mission

Nat Commun. 2018 Jan 18;9(1):289. doi: 10.1038/s41467-017-02558-1.

Authors

Antonio Genova^{1

2}, Erwan Mazarico³, Sander Goossens^{3

4}, Frank G Lemoine³, Gregory A Neumann³, David E Smith⁵, Maria T Zuber⁵

Affiliations

¹ Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. antonio.genova@nasa.gov.
² NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA. antonio.genova@nasa.gov.
³ NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA.
⁴ Center for Research and Exploration in Space Science and Technology, University of Maryland, Baltimore County, Baltimore, MD, 21250, USA.
⁵ Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.

Abstract

The NASA MESSENGER mission explored the innermost planet of the solar system and obtained a rich data set of range measurements for the determination of Mercury's ephemeris. Here we use these precise data collected over 7 years to estimate parameters related to general relativity and the evolution of the Sun. These results confirm the validity of the strong equivalence principle with a significantly refined uncertainty of the Nordtvedt parameter η = (-6.6 ± 7.2) × 10^-5. By assuming a metric theory of gravitation, we retrieved the post-Newtonian parameter β = 1 + (-1.6 ± 1.8) × 10^-5 and the Sun's gravitational oblateness, [Formula: see text] = (2.246 ± 0.022) × 10^-7. Finally, we obtain an estimate of the time variation of the Sun gravitational parameter, [Formula: see text] = (-6.13 ± 1.47) × 10^-14, which is consistent with the expected solar mass loss due to the solar wind and interior processes. This measurement allows us to constrain [Formula: see text] to be <4 × 10^-14 per year.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.