Even in these arid conditions, the planet may retain some microbial and possibly even multi-cellular life.

All Avalonian planets retained the antique tradition, except it was more than a tradition, since it really represented the servers pay.

The reason for this is that young planets retain heat from their formation, and only gradually cool.

"Do you see those suns out there, radiating their heat away and giving life to the planets yet always retaining it?"

The entire planet retained the casual, backwater flavor of an outlying province.

The star was young, barely four billion years old; the planet still retained a great deal of primordial heat, which supplemented the star's relatively weak insolation.

The radiation pressure of the solar wind then expelled most of the unaccreted matter, and only those planets with sufficient mass retained their gaseous atmosphere.

One is that a solid planet and a gas cloud retain different gases.

Stars, planets and moons retain their atmospheres by gravitational attraction.

Interstellar planets, theoretically, may also retain thick atmospheres.