We investigate the long-term dynamical stability of hypothetical moons orbiting extrasolar giant planets. Stellar tides brake a planet’s rotation and, together with tidal migration, act to remove satellites; this process limits the lifetimes of larger moons in extrasolar planetary systems. Because more massive satellites are removed more quickly than less massive ones, we are able to derive an ...

An orbiting 'photon clock' is proposed to test directly the relativity of simultane-ity of special relativity. This is done by comparison of the arrival times at a ground station of three microwave signals transmitted by two satellites following the same low Earth orbit. A similar experiment, that may be performed using synchronised signals from two GPS satellites with the receiver on a single ...

[1] Using densities measured by accelerometers on the CHAMP and GRACE satellites, and taking advantage of the local time precession characteristics of these near-polar orbiting satellites, exosphere temperatures are derived as a function of local time, longitude and latitude. Significant longitude variability (e.g., ±25K maximum to minimum over the equator) in geomagnetically-quiet exosphere te...

New redshift surveys of galaxies in the field of compact groups have discovered a population of faint galaxies which act as satellites orbiting in the potential well of the bright group. Here we analyze the mass distribution of the groups by comparing the mass derived from the bright members and the mass obtained from the satellite galaxies. Our analysis indicates the presence of a dark halo ar...

Global Positioning Systems (GPS) are satellite-based navigation systems that utilize a network of earth orbiting satellites. GPS operates well under any weather condition and does not require a subscription fee. GPS is a crucial component of precision agriculture by providing precise location information with very high repeatability. In recent years, GPS have improved in their level of performa...

In the near future GPS will be widely used thus allowing a broad variety of location dependent services such as direction giving navigation etc In this document we propose a family of protocols and addressing methods to integrate GPS into the Internet Protocol to enable the creation of location dependent services The solutions which we present are exible scalable in terms of the target accuracy...