Exploring Exoplanets, with Seth Shostak – StarTalk All-Stars

Seth Shostak and Chuck Nice in the StarTalk All-Stars Studio. Credit: Ben Ratner.

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About This Episode

Seth Shostak, SETI Institute Senior Astronomer and StarTalk veteran, is back to host StarTalk All-Stars as he and his co-host Chuck Nice welcome Jason Wright, Associate Professor of Astronomy at Penn State, to explore the exoplanets. Jason, who is a member at the Center for Exoplanets and Habitable Worlds, offers his insights on the important discovery of Proxima b, the neighboring exoplanet to Earth, roughly 4 light years away. We get details on what makes Proxima b special, space transportation by light sails and laser beams, and information on star KIC8462852, or as Seth calls it “Bob”. You’ll learn how the Kepler Space Telescope uses the dimming of stars to find planets, which bio-signatures we look for on exoplanets, and how coronagraphic telescopes work. Discover what signals SETI scans for, how long it would take to confirm a possible alien transmission, and the protocol SETI takes if a possible transmission is received. You’ll also find out about alien astro-architecture, “super Earths”, and whether it’s possible for non carbon-based life to exist. Plus, get the answers to Cosmic Queries like how do we detect life on an exoplanet? How many exoplanets have we visually seen? Are there planet types that are theorized but haven’t been discovered? A fan even asks, “Once you go alien, can you ever go back?”

NOTE: All-Access subscribers can watch or listen to this entire episode commercial-free here: Exploring Exoplanets, with Seth Shostak – StarTalk All-Stars.

In This Episode

  • Host

    Seth Shostak

    Seth Shostak
    All-Stars Host, Senior Astronomer at the SETI Institute
  • Co-Host

    Chuck Nice

    Chuck Nice
    Comedian
  • Guest

    Jason T. Wright

    Jason T. Wright
    Associate Professor of Astronomy and Astrophysics at Penn State, member of the Center for Exoplanets and Habitable Worlds

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Episode Topics

  • Drew

    I heard a mention about the use of a light sail and a large laser that can accelerate the space craft. Can we please stop thinking about these?

    Suppose that you have a laser that is 10 meters long. At the very tip of the laser, between the laser and the mount used to target the laser, you have a stray hydrogen atom that pushes the tip of the laser off by the diameter of the hydrogen atom. By Neptune, the laser pointer will be several kilometers off target. Then the question becomes, how do you correct for a hydrogen atom? Is that even possible? NOPE! So, something as small as a hydrogen atom makes these laser based systems impossible, unless we have absolutely perfect production processes…. I’d think there would be better space ships well before we have the required manufacturing tolerances. Which won’t be happening any time soon.

    • Bob Longmire

      I may be wrong, but it’s my understanding that the majority of the momentum imparted to the craft is done so in the first few hours after launch. IE, it leaves earth orbit with the velocity required to make the journey. This would eliminate the fine tracking issues you mentioned. I assume this brings in serious issues with G-forces during the acceleration, but that’s probably another matter.

      • Drew

        If you are sending people, the Gforce matters a lot. If you send robots, not so much. But, if a laser is that powerful, the sail need to be made by sufficiently strong material. I’ve seen lasers powerful enough to cut through 1″ thick steel. But, the push from that laser is nearly non exiatant.

        What I had heard about these laser sails was that they work like ion propulsion systems, small continuous acceleration.

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