Gravitational Shapiro Telescope on the PSR's period to discover Dark   Planets and Machos
  Collective Shapiro Phase Shift on the period of the pulsars due to a dark object (a passing MACHO or a planet) along the line-of-sight of one or more pulsar is a formidable gravitational tool to discover dark matter.We already noted that the presence of a few negative PSRs period, possibly due to such a Shapiro delay, is roughly consistent with independent estimates of MACHOs observed by microlensing in our Galaxy. Here we update our study and suggest to verify and to calibrate the Shapiro phase delay to observe on ecliptic main known planetary and solar gravitational fields. Once the test is probed we propose to use, in a collective way, a subsample of PSRs on the ecliptic plane to monitor our solar system for discovering any heavy unknown object, either dark Macho or planets. The importance of such unknown possible planetary components and their eventual near encounter with Earth in the far past (or future) should be not neglected : the same life evolution (or extinction) might be marked by such a rare event. 
D. Fargion, and R. Conversano