Rendezvous with Rama

"At first, only a few things are known about the celestial object that astronomers dub Rama. It is huge. It weighs more than ten trillion tons. And it is hurtling through the solar system as inconceivable speed. Then a space probe confirms the unthinkable: Rama is no natural object. It is, incredibly, an interstellar spacecraft. Space explorers and planet-bound scientists alike prepare for man's first encounter with alien intelligence." P. [4] of cover.