The Southern Ocean, which circles the globe without being blocked by land, is home to the Antarctic Circumpolar Current (ACC), the longest of the world's ocean currents. Also known as the "channel", it connects the Indian, Atlantic and Pacific Ocean basins and exerts a powerful influence over the Earth's climate. The ACC carries 150 times more water around Antarctica than the flow of all the world's rivers combined.

We feel it every moment of our lives but for physicists, gravity is the longest running unsolved mystery of the universe. Why do all objects that have mass pull on one another? Cutting-edge theories are proposing unexpected answers: Gravity could be another force in disguise, a thermodynamic mirage, or even, a shadow of a hidden holographic universe. If so, the force that holds us to the surface of the earth, and holds the earth in orbit around the sun, may be a trick of the mind. We feel it, but it may not be real. Is Gravity an Illusion?

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. The aging star will bloat out beyond the orbit of our planet incinerating all living things--including humans if we're still around.

When mankind eventually leaves the cradle of Earth and ventures forth into the uncharted territories of the cosmos, where, and what form, will our new homes take?

Is there another Earth out there with liquid oceans, rocky continents and life like us? Astronomers seek the answer with spectroscopy, direct imaging and telescopes. They hope to find evidence of atmospheres, magnetospheres and signs of life.

Imagine a tornado so powerful, it can form a planet, or winds sweeping across a planet but blowing at 6,000 miles per hour! How about rain....made of iron? Sounds like science fiction, but this type of weather is occurring daily in our solar system. Scientists are just beginning to unlock the secrets of these planets and their atmospheres. Can this research help scientists solve long unanswered questions that we have about Earth? As our own planet churns with the effects of global warming, it's natural to look into the heavens and wonder about the rest of the real estate.