Oceans in the Stars: A Search for Life on Other Planets

This article was published in advance of Aomawa Shields' April 8 lecture at NHMU, which is part of the Museum's 2025 Lecture Series. Tickets to her lecture are free with advance registration and can be reserved here.

By Olivia Barney

It’s human nature to search for belonging. We crave acceptance from our colleagues, peers, loved ones, and most importantly, ourselves. It’s all part of a great quest to find where we fit best within the universe: the space that excites our curiosities, utilizes our talents, and provides steppingstones for further growth. But the universe is a big place — 93 billion light years by current estimations — and that’s just the observable universe. Beyond what we can see, it continues on, and on, and on.

Portrait of Aomawa Shields, Ph. D. Steven Meckler

Just as complex as the cosmos is the process of identifying where we belong. In her memoir, “Life on Other Planets,” author Aomawa Shields, Ph.D., describes finding her place in the universe and the unexpected paths she took along the way. Growing up with a deep love for science and astronomy, she spent her undergraduate years at MIT, ultimately graduating with a Sc.B. in Earth, Atmospheric and Planetary Sciences. But soon after, two important events occurred: she began doubting her career choice, and she fell in love with storytelling and the performing arts. With a new trajectory mapped out, Shields obtained an MFA in acting from UCLA.

“When I left astronomy to pour myself into acting, I thought it was for good," she writes in her memoir. "But dreams don’t die. If left unpursued, they recede and then lie dormant. But they persist, nudge, sometimes elbow you right in the gut and demand to be acknowledged. That’s how it was for me. I fell in love with something, and I never really fell out.”

For 11 years, Shields explored her dream, but she couldn’t get the stars out of her mind. Acting and astronomy brought different kinds of light and excitement into her life, and she couldn’t see a future where she could pursue both careers. After years of oscillating between her two loves, Shields returned to the world of astronomy.

Life Beyond Earth’s Atmosphere

Shields is an astronomer and astrobiologist — someone who studies the potential for life (large or small) on other planets. She and her team focus on identifying the virtually universal factors that are needed to sustain life. Climate conditions that support liquid water are perhaps the most important of those considerations. All forms of life, from tiny microbes to towering elephants, rely on liquid water for survival.

The climate conditions of the Earth help scientists like Shields determine a range of similar climate conditions that could sustain liquid water on other planets. While our home planet (and solar system) is not the standard model within the universe, it is the planet we have the best ability to study. As technology expands, and as new discoveries are made across our galaxy, the knowledge we have of the Earth and our surrounding planetary neighbors will always remain important. “I am discovering that the more things get exciting out there, the more excitement I feel around our own solar system — and particularly Jupiter’s moon, Europa,” Shields said.

Artist's concept of Europa's mysterious interior: outer ice shell, a layer of liquid water, and a rocky interior, potentially with hydrothermal vents on the seafloor. NASA/JPL-Caltech

Europa is one of the four famous “Galilean satellites,” a name given to the first four of Jupiter’s 95 moons — and a tribute to Galileo Galilei, who was credited with their discovery in 1610. It’s roughly 90% the size of the Earth’s moon, and it’s the current subject of excitement within the world of planetary sciences.

Europa is covered in a shell of ice. Beneath its icy exterior, astronomers believe an enormous saltwater ocean lies — a body of liquid water that could be twice the amount on Earth. If true, Europa would be the most likely source for extraterrestrial life to exist within our solar system. The Europa Clipper, a spacecraft launched by NASA in October 2024 is scheduled to arrive in April 2030. The mission is a promising one, either providing Shields and her team with vital data to help them in their research or uncovering the discovery of a lifetime: liquid water or microscopic life outside of Earth.

Stars Shine in Many Colors

On May 25, 1961, President John F. Kennedy set a goal for the nation: perform a successful crewed moon landing and return to Earth. This lofty initiative led to eight years of focused, motivated efforts that culminated in the Apollo 11 launch on July 16, 1969. This age of space exploration sparked curiosity and excitement among a global audience, but the exploration hasn’t ended.

CapCom Charlie Duke (left), backup Commander Jim Lovell (next right), and backup Lunar Module Pilot Fred Haise (next to Lovell) in the MOCR during the Apollo 11 landing. NASA / Kip Teague

As Shields explores facets of the universe that were previously unknown, she’s often asked if, when, and how we’ll find life on other planets. It’s a complex question, but one Shields answers by first looking back at those early Apollo missions. “If you look at mission control and pictures of mission control back in the 1960s and early 70s, the demographic of that of that room was very homogeneous in terms of gender and race,” she said. “Think of what we were able to accomplish, and we only had a small subset of the population represented in that endeavor. Think of what we could accomplish if we allow everyone to be represented at the table. I think we're capable of anything.”

Shields is a fierce advocate for the dreamers, encouraging people worldwide to pursue their ambitions with grit, determination, and courage. Closer to home, she founded Rising Stargirls, an organization based out of UC Irvine that encourages “girls of all colors and backgrounds to learn, explore, and discover the universe.” Providing interactive astronomy workshops that combine elements of theater, writing, and visual arts, Rising Stargirls celebrates self-expression and scientific discovery — supporting the rising generation in their personal journeys to finding a place within the universe.

Discover the Stars With Shields

Explore the mysteries of the universe with Aomawa Shields, Ph.D., through NHMU’s 2025 Lecture Series and get an inside look at the latest research she’s conducting. Tickets to her April 8 lecture, “The Search for Life Beyond Earth,” are free with advance registration. There will be a book signing immediately following her talk, and a limited number of copies will be sold that evening at NHMU. To purchase a copy of her book in advance, click here.