Giant Magellan Telescope w/ Dr. Patrick McCarthy #043

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Today we had the privilege to discuss the Giant Magellan Telescope with Project Lead and Interim President, Dr. Patrick McCarthy. Dr. McCarthy shed a lot of light on what is involved in a project of this scope, what kind of scientific advances are likely to occur, as well as general information about how telescopes of all types actually work.


  • Why another telescope? We have so many. What is the Giant Magellan Telescope bringing that we haven’t had before?
    • Greater resolution through larger aperture
  • What are the big goals we hope to achieve with the Giant Magellan Telescope?
    • Distant galaxy observation (closer to the big bang)
    • Observing planets orbiting nearby stars
    • Identify planets with the chemical signatures of life
  • A recent report suggests that there is a planet orbiting Alpha Centauri, and that it might have liquid water. Could the Giant Magellan Telescope help us find out more?
  • How much of an optical compromise do earth-based telescopes experience compared to space-based? Or do they?
  • The mirrors are polished to 1 millionth of an inch. How do natural forces impact such a fine tolerance (i.e. shifting tectonic plates or even earthquakes, gravity, atmospheric pressure, ambient temperature, or even people walking by)?
    • Adaptive optics
  • Why this specific location in Chile?
  • The Giant Magellan Telescope is described the first of a new class of “Extremely Large Telescopes.” Is there a specific definition for ELTs?
  • Can you describe how the GMT will gather light via the mirror array, etc.?
    • Primary mirrors
    • Secondary mirrors
    • Final mirror
    • CCD
  • The mirrors are asymmetric. Why so?
  • The Giant Magellan Telescope has 7 massive mirrors, while the Thirty Meter Telescope and European Extremely Large Telescope were designed with hundreds of smaller mirrors. Why the choice of 7 large mirrors for GMT?
  • Can the system be upgraded over time, for instance a better CCD?
  • Aside from the visible spectrum, what else will the GMT see?
  • What other scientific instruments will be installed at the GMT complex?
  • How long before the GMT is operational?
  • How is the construction phase funded?
  • Once the GMT is up and running, how will it be funded?
  • Is there still room for other institutions to be involved?
  • Last question. In your opinion, are we alone?

For more info about the Giant Magellan Telescope project, head on over to!


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