This Week in Space

May 17th 2024

This Week in Space 111

The Big Glass Wars

Hosted by Rod Pyle, Tariq Malik

Inside the Race to Build the World's Largest Telescopes

New episodes posted every Friday.
Category: News

Welcome to the Big Glass Wars! That's right, just when you thought you'd heard it all, turns out there's hot competition among a few countries to stay on the cutting edge of optical astronomy, and to do that, you need a great big hunk of glass to gather light from distant galaxies and stellar systems. Enter the Carnegie Observatories and their partners on the Thirty Meter Telescope and the Giant Magellan Telescope. Both are currently under construction, and both are threatened by budget parsimony from the U.S. Congress. Dr. John Mulchaey, Director of the Carnegie Observatories, joins us to discuss what's happening, why it matters, and what you can do to help maintain U.S. leadership in astronomy, cosmology, and other STEM-related fields.


  • Boeing’s Starliner launch to the ISS delayed again, this time due to a helium leak in the service module. The launch is now targeted for no earlier than May 21st.
  • Blue Origin plans to conduct its first crewed suborbital flight since August 2022 on May 19th, carrying six passengers including the first Black astronaut candidate Ed Dwight.
  • A massive sunspot caused spectacular auroras visible as far south as Alabama and turned skies purple and orange. More solar activity is expected as another large sunspot emerges.

Main Topic: The Big Glass Wars with Dr. John Mulchaey

  • Dr. Mulchaey provides an overview of the Carnegie Observatories, founded in 1904, and their historic telescopes at Mount Wilson that helped launch modern astronomy.
  • He discusses the need for extremely large next-generation ground-based telescopes, the Giant Magellan Telescope (GMT) and Thirty Meter Telescope (TMT), to study earth-like exoplanets and the early universe.
  • These ambitious segmented mirror telescopes will be 5-10 times larger than today’s biggest telescopes and cost billions of dollars to construct.
  • While substantial private funding has been raised, the projects need investment from the National Science Foundation (NSF) and the U.S. government to be completed. However, the NSF has proposed only partial funding.
  • Dr. Mulchaey emphasizes the importance of the U.S. having both telescope projects to provide full-sky coverage, double the observation time, and maintain the nation’s leadership in astronomy research or risk losing top talent to competing projects in Europe and China.
  • He notes that delaying a decision on full funding is causing the estimated costs to escalate as the projects are forced to wait.
  • Dr. Mulchaey argues passionately that inspiring the next generation of scientists and engineers by investing in these telescopes is critical for the country’s future productivity and innovation.

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