Observational Proof That Mercury Occupies A Cassini State

Details Observational Proof That Mercury Occupies A Cassini State Observational Proof That Mercury Occupies A Cassini State

Sep 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006dps....38.4905m&link_type=abstract

American Astronomical Society, DPS meeting #38, #49.05; Bulletin of the American Astronomical Society, Vol. 38, p.576

Astronomy and Astrophysics

Astronomy

Scientific paper

Mercury is expected to be in a Cassini state in which its orbit pole, spin orientation, and normal to the Laplacian plane remain coplanar [Peale 1988]. Although numerical simulations [Yseboodt and Margot 2006, Peale 2006] support this theoretical prediction, it has never been confirmed observationally. The problem is important because the end-state of evolution in a Cassini state is strongly dependent on the distribution of mass inside the body. If Mercury is in a Cassini state, it may be possible to characterize the size and state of the core by measuring spin and gravity parameters [Peale 1976], which is one of the MESSENGER mission goals. Here we present new radar data that make a very compelling case for the occupancy of Cassini state 1, dwarfing uncertainties of previous ground-based and space-based measurements by orders of magnitude. The radar technique relies on theoretical developments described by Green [1961, 1968] and Holin [1988, 1992]. The idea is to observe wavefront corrugations tied to the rotation of Mercury at two widely separated telescopes. The time of day at which a correlation is observed provides a strong handle on the spin axis orientation.
The data acquired so far at the Goldstone and Green Bank telescopes yield an accurate solution for the spin orientation. The uncertainty contours fall precisely on the locus of points obeying the Cassini state configuration.

Affiliated with

Also associated with

No associations

Rating

Observational Proof That Mercury Occupies A Cassini State does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Observational Proof That Mercury Occupies A Cassini State, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observational Proof That Mercury Occupies A Cassini State will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1001133