The System of Molecular Clouds in the Gould Belt
  Based on high-latitude molecular clouds with highly accurate distance
estimates taken from the literature, we have redetermined the parameters of
their spatial orientation. This system can be approximated by a 350x235x140 pc
ellipsoid inclined by the angle i=17+/-2 degrees to the Galactic plane with the
longitude of the ascending node l{\Omega}=337+/-1 degrees. Based on the radial
velocities of the clouds, we have found their group velocity relative to the
Sun to be (u0,v0,w0) = (10.6,18.2,6.8)+/-(0.9,1.7,1.5) km/s. The trajectory of
the center of the molecular cloud system in the past in a time interval of ~60
Myr has been constructed. Using data on masers associated with low-mass
protostars, we have calculated the space velocities of the molecular complexes
in Orion, Taurus, Perseus, and Ophiuchus. Their motion in the past is shown to
be not random.
