Once they were dreaded and thought to be dragons eating the sun--but modern science has dispelled mythology, and we now look forward to total Solar Eclipses as one of the most spectacular phenomena in the heavens.

Scientists have no idea what it is, but Dark Matter and Dark Energy make up 96% of the Universe. Dark Matter is everywhere. It passes through everything we know on earth at billions of particles every second.

What might happen if the first manned mission to Mars crashes hundreds of miles from the rocket that would take them back home? Could they survive the crash, and travel across the brutal Martian surface to their home ship?

It is a fireball in the sky, a bubbling, boiling, kinetic sphere of white hot plasma, exploding and erupting. Its size is almost unimaginable--one million Earths would fit within its boundaries.

Could there be a monstrous, undiscovered star orbiting our own Sun? Could it be scattering killer comets throughout our Solar System like clockwork every 26 million years?

Our Sun has served Earth well for almost five billion years. It's bathed us with heat and energy. But like humans, our home star is mortal. In five billion years, it will stop nurturing its planetary offspring.

At 4.6 billion years old, the Solar System is our solid, secure home in the Universe. But how did it come to be? In this episode we trace the system's birth from a thin cloud of dust and gas.

For most, it's the deadly centerpiece of the film Star Wars. But in truth, real death stars are in the final stage of life before they explode into supernovae and, occasionally, the biggest blast in the universe--the gamma ray burst (GRB).