It also has the highest mass of all planetary satellites, with 2.02 times the mass of the Earth's moon.

The two moons, with respective diameters estimated at only 50 and 100 miles, are the faintest planetary satellites ever detected from the ground.

There he worked on the orbits of planetary satellites using the 26-inch (66-cm) telescope, the great refractor of his father's discoveries.

Molecules may be found in many environments, however, from stellar atmospheres to those of planetary satellites.

It is also the only regular planetary natural satellite in the Solar System known not to be tidally locked.

Nereid's orbit is cometlike; very unusual for a planetary satellite.

One of the first questions to be asked was whether it possessed an atmosphere, thus making it unique among the planetary satellites.

His work includes analysis of brown dwarfs, gas giants, and planetary satellites.

Item six: a functioning satellite planetary navigation system.

A total of 172 planetary satellites (including those of Pluto but not Earth) are represented below.