20 years ago, two astronomers made a remarkable discovery, one which would change the way we view the universe for ever. A planet outside our solar system, orbiting a distant star - an exoplanet. Since then, we have found worlds where it rains diamonds, ones that boil at 3,000 degrees centigrade and even a world with four suns in its sky. But the big question is - will we ever find another Earth? As we close in on the discovery of the 2,000th planet outside our solar system, or exoplanet, we investigates the techniques that are revealing so much about these alien worlds. The documentary asks if we are really any closer to finding another world like our own - a second Earth.

Playing with Nuclear Fire' - In March 2011, the Tohoku earthquake in Japan created a tsunami that killed some 16,000 people and crippled the Fukushima Daiichi nuclear power plant. In the aftermath, the government and TEPCO, the plant's operator, withheld information about the extent of the damage. Three years later, citizens and the international community are left wondering if Japan really does have the situation under control, as the government is insisting, or if the danger is far greater than anyone is willing to admit. 'No Man Left Behind' - It's estimated that over a quarter million vets from recent wars have sought treatment for PTSD. Despite these statistics, veterans often face an uphill battle to get treatment, receiving inadequate attention and, most dangerously, overprescribed narcotics and other pharmaceuticals. Ryan Duffy meets veterans struggling with mental illness and addiction.

This episode provides an overview of the nature of electromagnetism, as discovered through the work of Michael Faraday. Tyson explains how the idea of another force of nature, similar to gravitational forces, had been postulated by Isaac Newton before. Tyson continues on Faraday, coming from poor beginnings, would end up becoming interested in studying electricity after reading books and seeing lectures by Humphry Davy at the Royal Institution. Davy would hire Faraday after seeing extensive notes he had taken to act as his secretary and lab assistant. After Davy and chemist William Hyde Wollaston unsuccessfully tried to build on Hans Christian Ørsted's discovery of the electromagnetic phenomena to harness the ability to create motion from electricity, Faraday was able to create his own device to create the first electric motor by applying electricity aligned along a magnet. Davy, bitter over Faraday's breakthrough, put Faraday on the task of improving the quality of high-quality optical glass, preventing Faraday from continuing his research. Faraday, undeterred, continued to work in the Royal Institution, and created the Christmas Lectures designed to teach science to children. Following Davy's death, Faraday returned to full time efforts studying electromagnetism, creating the first electrical generator by inserting a magnet in a coil of wires. Tyson continues to note that despite losing some of his mental capacity, Faraday concluded that electricity and magnetism were connected by unseen fields, and postulated that light may also be tied to these forces. Using a sample of the optical glass that Davy had him make, Faraday discovered that an applied magnetic field could affect the polarization of light passing through the glass sample (a dielectric material), leading to what is called the Faraday effect and connecting these three forces. Faraday postulated that these fields existed across the planet, which would later by called Earth's magnetic field generated by the rotating molten iron inner core, as well as the phenomena that caused the planets to rotate around the sun. Faraday's work was initially rejected by the scientific community due to his lack of mathematical support, but James Clerk Maxwell would later come to rework Faraday's theories into the Maxwell's equations that validated Faraday's theories. Their combined efforts created the basis of science that drives the principles of modern communications today.

We are the most power-hungry generation that has ever lived. This film tells the story of how that power has been harnessed - from wind, steam and from inside the atom. In the early years the drive for new sources of power was led by practical men who wanted to make money. Their inventions and ideas created fortunes and changed the course of history, but it took centuries for science to catch up, to explain what power is, rather than simply what it does. This search revealed fundamental laws of nature which apply across the universe, including the most famous equation in all of science, e=mc2.

Muhammad Ali was arguably the greatest boxer of the 20th century, and that rare fighter whose presence in the culture of the day was equal to (or perhaps even greater than) his remarkable skills in the ring. Ali was a superb fighter who squared off against a variety of gifted athletes during his career, and filmmaker Pete McCormack offers a new perspective on Ali through this documentary, in which some of his opponents speak about their experiences with the man. Facing Ali includes interviews with Joe Frazier, who speaks of the bitterness that still remains of his rivalry with Ali; George Chuvalo, a Canadian fighter who recalls that while Ali defeated him, he went dancing with his wife afterward while the winner went to the hospital; George Foreman, whose memories include a powerful punch that Ali chose not to land; Leon Spinks, whose 1978 upset victory over Ali thrust him into a level of fame he was not prepared to handle; Ernie Terrell, who discusses the technique and strategy behind Ali's approach; and many more.

Could nuclear fusion hold the answers to the energy crisis? It is the process that has forged all matter in the universe. It lights the stars and it is what transformed the lighter atoms that formed in the Big Bang into heavier atoms. In Can We Make a Star on Earth?, Brian Cox peers beyond the glare of our Sun to reveal the hidden forces that provide its power. He discovers how this fusion energy has kept our closest star burning for five billion years. Brian believes humanity must build a star on Earth to ensure survival. Will scientists be able to harness fusion power and achieve abundant, cheap, clean energy?