On alien planets, they rain from the sky as scalding iron. On distant moons, even at hundreds of degrees below zero, they slosh around in pristine lakes of methane. They can cover entire planets in mi

Outer space is already an essential part of America\’s ability to fight wars. Our military depends on satellites for many things, such as communications, reconnaissance and targeting information. But

They are the one-stop-shopping places for learning all about the nature and variety of stars in the Universe. They\’re unique, because in clusters, all the stars were born at about the same time, from

Experts cook up ways you could destroy the Earth, including swallowing it with a black hole, blowing it up with anti-matter, hurling it into the Sun, and switching off gravity.

They are breathtaking, lethal and a constant source of surprise. The stunning rings of Saturn have mesmerized countless scientists over the centuries. With particles the size of a house shooting at 53

Airdate: 17 January, 2010
Summary: Sarah begins to find a new love interest. Kevin and Scotty wait for news on their surrogacy. Kitty and Robert disagree on political views.

The Universe is full of explosions that both create and destroy. The Chicxulub impact on the Yucatan peninsula, which may have wiped out the dinosaurs 65 million years ago, was two million times more

Airdate: 10 January, 2010
Summary: Sarah takes a shine to a divorced dad at Paige\’s school. Justin finds a way to overcome his learning difficulties.

Every year, thousands of objects both natural and manmade plummet through our atmosphere and crash into the Earth. These menacing messengers from the sky provide scientists with amazing insights into

Airdate: 3 January, 2010
Summary: As Kitty\’s lymphoma reaches a critical stage, the Walkers\’ frantic search for a marrow donor may lead to an unlikely source.