Dear Fermi: A Fan Letter

MY FAVORITE SPACECRAFT? THE FERMI GAMMA-RAY SPACE TELESCOPE, WHICH CAPTURES A COSMOS SO DIFFERENT FROM WHAT OUR EYES SEE.

- LIZ KRUESI

IN THE SUMMERS OF MY CHILDHOOD, I spent time in upstate New York at my grandparents’ lakeside home, far from the polluting light of big cities. At night, I would pull a blanket from my bed and drag it down the pine needle–covered path from the house to the boat dock. Stretched out there, I would gaze at the star-filled sky for as long as the grown-ups allowed. I didn’t have words for what I was feeling: the pull of the cosmos, beautiful and awe-inspiring.

Fast-forward more than a decade to summer 2002, when I first learned of astronomy in the extreme, energetic and exciting. I was a summer intern at the University of Chicago, an institution known for its physics pioneers. Among them: Enrico Fermi, who spent the last years of his life and career there.

At UChicago, I rehabbed equipment designed to detect cosmic rays, the high-energy protons and other nuclei that bombard us from space. I learned of gamma rays—the most energetic form of light—and how detecting them takes creativity, innovation, and observatories lofted into space. I was hooked. Six years later, just such an observatory launched from Florida atop a Delta II rocket and into orbit around Earth. Named for Fermi, it’s become my favorite spacecraft.

The Fermi Gamma-ray Space Telescope has shown me a universe I could never have dreamed, a brilliant, violent realm buzzing with beauty and movement. Fermi sees a cosmos so different from what my eyes capture—a stunning departure from the visible light emitted by the screen in my hand and the screen on my wall and the screen on my desk.