Many of the greatest Hispanic scientists are people you may not have learned about in school. From groundbreaking biologists and physicists to innovators in the fields of medicine, botany, and environmental studies, here are 10 game-changing Hispanic scientists you should know about.

1. Carlos Juan Finlay

Today, the world recognizes Cuban doctor and scientist Carlos Juan Finlay as a pioneer in the study of yellow fever. But back in 1881, when Finlay first presented his extensive research suggesting that mosquitoes transmitted the disease to Havana’s Academy of Sciences, he became a laughingstock. According to Finlay’s son, the speech was greeted with initial silence, followed by “universal ridicule.” It took another two decades before Finlay’s hypothesis became widely accepted. During that time, Finlay didn’t give up on his research. Instead, he spent those 20 years refining his theory, breeding mosquitoes, and conducting hundreds of tests to support this theory.

2. Mario J. Molina

The first Mexican-born scientist to win a Nobel Prize in Chemistry, Mario Molina discovered the serious environmental threat posed by chlorofluorocarbon gases (CFCs). Along with fellow chemist Sherwood Rowland, Molina found that CFCs—chemicals commonly used as refrigerants, and colloquially known as Freon—released into the atmosphere were contributing to ozone depletion.

3. Ellen Ochoa

In 1993, astronaut Ellen Ochoa became the first Hispanic woman to go to space. She first served on a nine-day mission aboard the space shuttle Discovery, where she and a team of astronauts studied Earth’s ozone layer, then returned to space three more times, spending nearly 1000 hours in orbit. Ochoa, who was honored with NASA’s Distinguished Service Medal, served as the director of the Johnson Space Center in Houston, Texas, from 2013 to 2018.

4. César Milstein

Nobel Prize-winning biochemist César Milstein opened new doors in the diagnosis and treatment of disease with his 1975 study on monoclonal antibodies. Milstein and his team developed a technique for the unlimited production of monoclonal antibodies, a type of antibody made by identical immune cells. Thanks to Milstein’s work, monoclonal antibodies are now used in everything from diagnostic tests to the treatments of several autoimmune diseases to alleviating COVID-19.

5. France A. Córdova

Astrophysicist France A. Córdova was the director of the National Science Foundation, a federal agency that develops programs to advance all fields of scientific discovery, from 2014 to 2020. She was nominated for the position by President Barack Obama. Before she spent her days overseeing America’s science and scientific education programs, Córdova conducted important research on X-ray and gamma ray sources, accretion discs, and black holes, publishing more than 150 scientific papers. Back in 1993, she also became the first woman to hold the position of NASA Chief Scientist.

6. Ynes Mexia

Mexican-American botanist Ynes Mexia discovered two new plant genera and 500 new plant species—and she didn’t even start collecting plants until she was 51 years old [PDF]. Born in 1870 in Washington D.C. to a Mexican diplomat father, Mexia spent many years as a social worker before enrolling as an undergraduate at the University of California Berkeley and discovering her passion for botany. In the 1910s and 1920s, she traveled thousands of miles around Mexico, South America, and Alaska, collecting some 145,000 plant specimens in just 13 years. Today, 50 plant species are named for her.

7. Juan M. Maldacena

Born in Buenos Aires in 1968, physicist Juan M. Maldacena studies the relationship between quantum gravity and quantum field theories. Currently a faculty member at the Institute for Advanced Studies, he has been awarded the Fundamental Physics Prize (2012) and appeared on the “Einstein’s Dream” episode of PBS’s Big Ideas. Maldacena’s research on the duality of conjecture was so groundbreaking, the participants of a 1998 string theory conference wrote a song to honor him called “The Maldacena” (sung and danced to the tune of “The Macarena.” It was the 1990s, after all). While much of Maldacena’s work is tough reading for non-physicists, he has also written several explanations of his work on quantum theory for general audiences, including a popular 2007 Scientific American article tantalizingly entitled “The Illusion of Gravity.”

8. Albert Baez

Father of singers Joan Baez and Mimi Fariña, Mexican-American physicist Albert Baez was the co-inventor of the X-ray reflection microscope. Though he created the device, which allows scientist to examine living cells, in 1948, it’s still considered a crucial scientific tool to this day. A pacifist, he refused a series of defense industry positions during the Cold War arms race, instead conducting research and teaching physics at the University of the Redlands, Baghdad University, MIT, and Harvey Mudd College.

9. Helen Rodríguez Trías

Born in New York City in 1929, Puerto Rican-American pediatrician and healthcare advocate Helen Rodríguez Trías helped improve access to public health services for women and children in both the United States and Puerto Rico. She was the first Hispanic president of the American Public Health Association as well as a founding member of the Committee to End Sterilization Abuse, an organization that fought against the practice of forced sterilization. In 2001, she was awarded the Presidential Citizen’s Medal for her work on behalf of people with HIV and AIDS.

10. Alfonso Caso y Andrade

Born in Mexico City in 1896, Alfonso Caso y Andrade left a career as a legal scholar to pursue his passion: understanding the nature and evolution of Mexico’s pre-Hispanic cultures [PDF]. As an archaeologist, he fought against a prevailing idea that Mesoamerican cultures must have developed from the expansion of ancient Egyptian or Chinese cultures. He argued that evidence showed Indigenous peoples in the Americas formed their own cultures, independently of those in the Old World. His research in Oaxaca led to the excavation of Monte Albán, a major Zapotec city dating from about 500 BCE, and the discovery of Tomb 7, which contained finely carved objects and tools. The findings shed new light on the sophistication and development of pre-Hispanic peoples in Mexico and cemented Caso’s reputation as a leading archaeologist.

This story originally ran in 2016. It has been updated for 2021.