playlist

Are we alone in the universe?

Is Earth really the only life-sustaining planet? These speakers think there might just be something or someone else out there — and urge us to keep looking for it.

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  1. 21:23
    Jill Tarter Join the SETI search

    The SETI Institute's Jill Tarter makes her TED Prize wish: to accelerate our search for cosmic company. Using a growing array of radio telescopes, she and her team listen for patterns that may be a sign of intelligence elsewhere in the universe.

  2. 10:39
    James Green 3 moons and a planet that could have alien life

    Is there life beyond Earth? Join NASA's director of planetary science James Green for a survey of the places in our solar system that are most likely to harbor alien life.

  3. 3:29
    Carolyn Porco Could a Saturn moon harbor life?

    Carolyn Porco shares exciting new findings from the Cassini spacecraft's recent sweep of one of Saturn's moons, Enceladus. Samples gathered from the moon's icy geysers hint that an ocean under its surface could harbor life.

  4. 13:46
    Tabetha Boyajian The most mysterious star in the universe

    Something massive, with roughly 1,000 times the area of Earth, is blocking the light coming from a distant star known as KIC 8462852, and nobody is quite sure what it is. As astronomer Tabetha Boyajian investigated this perplexing celestial object, a colleague suggested something unusual: Could it be an alien-built megastructure? Such an extraordinary idea would require extraordinary evidence. In this talk, Boyajian gives us a look at how scientists search for and test hypotheses when faced with the unknown.

  5. 18:29
    Penelope Boston There might just be life on Mars

    So the Mars Rovers didn't scoop up any alien lifeforms. Scientist Penelope Boston thinks there's a good chance — a 25 to 50 percent chance, in fact — that life might exist on Mars, deep inside the planet's caves. She details how we should look and why.

  6. 19:11
    Freeman Dyson Let's look for life in the outer solar system

    Physicist Freeman Dyson suggests that we start looking for life on the moons of Jupiter and out past Neptune, in the Kuiper belt and the Oort cloud. He talks about what such life would be like — and how we might find it.

  7. 18:40
    Seth Shostak ET is (probably) out there — get ready

    SETI researcher Seth Shostak bets that we will find extraterrestrial life in the next twenty-four years, or he'll buy you a cup of coffee. He explains why new technologies and the laws of probability make the breakthrough so likely — and predicts how the discovery of civilizations far more advanced than ours might affect us here on Earth.

  8. 6:38
    Jeremy Kasdin The flower-shaped starshade that might help us detect Earth-like planets

    Astronomers believe that every star in the galaxy has a planet, one fifth of which might harbor life. Only we haven't seen any of them — yet. Jeremy Kasdin and his team are looking to change that with the design and engineering of an extraordinary piece of equipment: a flower petal-shaped "starshade" positioned 50,000 km from a telescope to enable imaging of planets about distant stars. It is, he says, the "coolest possible science."

  9. 16:02
    Nathalie Cabrol How Mars might hold the secret to the origin of life

    While we like to imagine little green men, it's far more likely that life on other planets will be microbial. Planetary scientist Nathalie Cabrol takes us inside the search for microbes on Mars, a hunt which counterintuitively leads us to the remote lakes of the Andes mountains. This extreme environment — with its thin atmosphere and scorched land — approximates the surface of Mars about 3.5 billion years ago. How microbes adapt to survive here may just show us where to look on Mars — and could help us understand why some microbial pathways lead to civilization while others are a dead end.