Constraints on MOND theory from radio tracking data of the Cassini
  spacecraft
  The MOdified Newtonian Dynamics (MOND) is an attempt to modify the
gravitation theory to solve the Dark Matter problem. This phenomenology is very
successful at the galactic level. The main effect produced by MOND in the Solar
System is called the External Field Effect parametrized by the parameter $Q_2$.
We have used 9 years of Cassini range and Doppler measurements to constrain
$Q_2$. Our estimate of this parameter based on Cassini data is given by $Q_2=(3
\pm 3)\times 10^{-27} \ \rm{s^{-2}}$ which shows no deviation from General
Relativity and excludes a large part of the relativistic MOND theories. This
limit can also be interpreted as a limit on a external tidal potential acting
on the Solar System coming from the internal mass of our galaxy (including Dark
Matter) or from a new hypothetical body.
