More than 100 years ago, astronomer George Ellery Hale brought two Pasadena institutions together to build what was then the largest optical telescope in the world. The Mount Wilson Observatory changed the conception of humankind's place in the universe and revealed the mysteries of the heavens to generations of citizens and scientists alike. Ever since then, the United States has been at the forefront of "big glass."

In fact, the institutions, Carnegie Science and Caltech, still help run some of the largest telescopes for visible-light astronomy ever built.

But that legacy is being threatened as the National Science Foundation, the federal agency that supports basic research in the U.S., considers whether to fund two giant telescope projects. What's at stake is falling behind in astronomy and cosmology, potentially for half a century, and surrendering the scientific and technological agenda to Europe and China.

In 2021, the National Academy of Sciences released Astro2020. This report, a road map of national priorities, recommended funding the $2.5 billion Giant Magellan Telescope at the peak of Cerro Las Campanas in Chile and the $3.9 billion Thirty Meter Telescope at Mauna Kea in Hawaii.