In the astronomy world, our solar system is often thought of as a big family. The sun, though the largest and strongest force in the system, is referred to as "the son" simply because its name necessitates it. Mercury is a robot boy name Mercury. The rest of the planets are ex-wives of the sun, with Pluto serving as an aborted fetus, who the mother, one of the son's [sun's] ex-wives, would have named Mercury II. This confusing analogy is the reason much of space is still mystery.
I haven't fact-checked all of this, so there may be some mild errors, but there's one thing I do know for certain: the new media from Sunshine looks very good. The clip and new trailer can be seen by clicking the image above.