Extras

    Video thumbnail: NOVA Early Earth Bombarded By Comets

    NOVA

    Early Earth Bombarded By Comets

    Comets carrying chemicals necessary for life may have come to Earth billions of years ago.

    Early Earth Bombarded By Comets

    Video thumbnail: NOVA Hunting Planets

    NOVA

    Hunting Planets

    NASA’s Kepler mission lets us search for planets orbiting stars outside our solar system.

    Hunting Planets

    Video thumbnail: NOVA Is There Life on Enceladus?

    NOVA

    Is There Life on Enceladus?

    Scientists discover evidence for the key ingredients for life on Saturn's moon Enceladus.

    Is There Life on Enceladus?

    Video thumbnail: NOVA Finding Life Beyond Earth Preview

    NOVA

    Finding Life Beyond Earth Preview

    Scientists are on the verge of answering one of the greatest questions: Are we alone?

    Finding Life Beyond Earth Preview

    Video thumbnail: NOVA An Interview with Sally Ride

    NOVA

    An Interview with Sally Ride

    Watch an uncut interview with the late astronaut, conducted at NASA in 1984.

    An Interview with Sally Ride

    Video thumbnail: NOVA The Mars Rover, "Curiosity"

    NOVA

    The Mars Rover, "Curiosity"

    NASA is sending a robotic rover called "Curiosity" to find out if there is life on Mars.

    The Mars Rover, "Curiosity"