When world-renowned UCLA astrophysicist Andrea Ghez set out to map the heart of our galaxy, skeptics told her it couldn’t be done. Today she stands among science’s elite: a 2020 Nobel laureate — just the fourth woman ever awarded the prize in physics — for her pioneering discovery of the supermassive black hole at the center of the Milky Way.
Ghez’s supermassive discovery has transformed our understanding of the formation, growth and dynamics of galaxies and deepened what we know about the laws of physics and the universe.
Her early fascination with the mysterious center of the Milky Way led her to develop advanced imaging tools to peer through cosmic dust and distortion.
“How do you observe something you can’t see?” asks Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics. “That’s an essential question when you want to find and study black holes, because black holes are objects whose pull of gravity is so intense that nothing can escape them — not even light.”
Because Earth’s atmosphere blurs our view of the rest of the universe — Ghez likens it to looking at a pebble through rippling water — she helped pioneer adaptive optics, a technology that corrects these distortions in real time, delivering crystal-clear images of stars swirling around the galactic center.
Those tools allowed her to track these stellar orbits for years at the W.M. Keck Observatory in Hawaii, with support from UCLA, the University of California, the National Science Foundation and other sources. Ghez and her team were ultimately able to gather compelling proof: a massive, invisible object — 4 million times the sun’s mass — holding those stars by gravitational force. It was the clearest evidence yet of a supermassive black hole.
Ghez describes how through perseverance she was able to bring together more than a hundred collaborators from around the world to ask and answer important questions. And that same perseverance helped sustain her through the initial skepticism about her project for developing methods to find and study black holes — and ultimately secure more funding. On that score, she says, she has a favorite saying: Every challenge is an opportunity.
“Our project didn’t seem important to a lot of people, but the University of California and UCLA gave us the tools to look deep into the universe, and we were able to bring something incredible into focus,” she says. “We showed the world something that’s impossible to see directly and discovered more questions than answers. And that’s what UCLA does every day. We ask questions. We explore those things still shrouded in darkness, and we bring new knowledge and understanding into focus. And I’m so proud and grateful to be part of this incredible institution.”
Nobel laureate Professor Andrea M. Ghez recounts the groundbreaking journey that revealed a supermassive black hole nestled at the center of our galaxy. Through innovative technologies like adaptive optics and decades of high-resolution stellar observations, Dr. Ghez and her team transformed what was once mere theory into undeniable discovery.
