Lecture 28: The Galilean Moons of Jupiter

Among the 61 known moons of Saturn, two stand out: Enceladus and Titan. Giant Titan is the only moon in our Solar System with a substantial atmosphere, composed of nitrogen and methane, dense enough to maintain a weather cycle with methane analogous to the water cycle on Earth, e ...  Show more

Why is the Earth habitable today but Venus and Mars not? This lecture explores the question of planetary habitability from the perspective of the stability of liquid water on the surface of planetary bodies. We will see how the amount of sunlight and the greenhouse effect in the ...  Show more

Melvyn Bragg and guests discuss the life cycle of stars. In his poem Bright Star John Keats wrote, "Bright Star, would I were steadfast as thou art". For Keats the stars were symbols of eternity- they were beautiful and ordered and unchanging - but modern astronomy tells a very d ...  Show more

Are we alone in the Universe? This lecture explores the question of how we might go about finding life on planets around other stars. Rather than talking about speculative ideas, like the Drake Equation or SETI, I am instead taking the approach of posing it as a problem of what t ...  Show more

Melvyn Bragg and guests discuss the abrupt transformation of stars after shining brightly for millions or billions of years, once they lack the fuel to counter the force of gravity. Those like our own star, the Sun, become red giants, expanding outwards and consuming nearby plane ...  Show more

Melvyn Bragg and guests discuss the abrupt transformation of stars after shining brightly for millions or billions of years, once they lack the fuel to counter the force of gravity. Those like our own star, the Sun, become red giants, expanding outwards and consuming nearby plane ...  Show more