Astronomer Vera Rubin changed the way we look at the universe by showing that galaxies are mostly dark matter.
On a dry and clear night at the Kitt Peak Observatory in the mountains of southern Arizona, Rubin observed the spectra of stars in the Andromeda Galaxy to determine their velocities. The conditions for the observation were perfect, if not the heat rising from the Sonoran Desert. Rubin alternated between eating ice cream cones and developing shots that were being taken by her colleague Kent Ford on the observation deck. It was their first successful night, when they discovered how fast the stars of the galaxy are spinning around their center (which astronomers call the rotation curve). It was 1
"The surprises came very quickly," Rubin recalled years later in a written report about her life. "At the end of the first night, we were confused about the shape of the rotation curve."
The rotation curve was flat, which meant that the stars in the outer spirals of the galaxy circled at the same speed as stars near the center. Even more alarming was the fact that the stars in the outer spirals were circling so fast that they should have dispersed. The mass of visible stars was not enough to hold the galaxy together. There was a great deal of matter missing.
The Andromeda galaxy was the first of many galaxies with inexplicable rotation curves that Rubin observed at Ford. Rubin's decades of discoveries have shown that the universe has much more to offer than the eye suggests. The cosmos was full of dark matter .
Uncovering the Darkness
The Swiss astronomer Fritz Zwicky first proposed the existence of dark matter in 1933 after observing the movement of galaxies in the ] Coma Cluster . The clusters of galaxies he observed would have had to diverge if there had been no extra mass holding them together. Lacking further evidence, his idea was quickly rejected by the scientific community.
Thanks to Rubin's work, scientists today believe that only about 20% of matter is visible in the Universe. The other 80% are dark matter.
But what is dark matter?
"We do not know," said Regina Caputo, astrophysicist at NASA's Goddard Space Flight Center. "We know what it is not, it's not normal stuff like protons, neutrons, electrons, neutrinos, we know it's stable, we know it's not loaded, we have a number of masses that it can be, but we have not figured it out yet. "
Inspired by Rubin, Caputo spent most of her career discovering dark matter. She is currently using gamma-ray observations from the Fermi Gamma-Ray Space Telescope to find signs of dark matter in the hearts of galaxies.
Rubin's early years
Rubin's affinity to astronomy began at a young age. It was born on July 23, 1928, from two Jewish immigrant parents who supported Rubin's scientific interests from the start. Her father helped her to build a paper telescope to photograph the movement of stars. Her mother persuaded the librarian that Rubin check out the scientific books from the adult library section of the local library. But above all, it was Rubin's immortal curiosity that drove her.
"Around the age of twelve, I would rather stay up and watch the stars go to sleep," Rubin said in an 1989 interview with Alan Lightman . . "I started learning, I started going to the library and reading, but at first I just watched the stars from my bedroom, there was nothing interesting in my life other than watching the stars every night."
Her willingness to learn always overshadowed the loneliness she felt as a woman in the field of astronomy. According to American Museum of Natural History Rubin was the only astronomy student in her graduating class from 1948 at Vassar College for Women in New York. When she tried to apply for a graduate school in Princeton, she was rejected because the astronomy program did not accept female students. Unmoved, she attended Cornell and Georgetown Universities for graduate schools.
In Georgetown, she had to reconcile family and research. She began her doctorate with one child to be cared for and another on her way, taking lessons at night. Her husband, Robert Rubin, drove her to university and waited in the car while studying.
Years later, she was the first woman allowed to observe at the famous Palomar Observatory Observatory Fritz Zwicky used to watch the coma cluster. Seeing that the only bathroom in the observatory was labeled "MEN", she drew a woman in a skirt and pasted it over the door.
Rubin's research during her early career was largely unacknowledged by her colleagues. Her master's thesis on the large-scale movements of galaxies was controversial. Her doctoral thesis was largely ignored.
In order to avoid more competitive or controversial areas of research, Rubin began exploring the rotation of galaxies. This led Rubin to a permanent position at the Carnegie Institution in Washington, DC, where she met and joined Kent Ford.
Rubin continued her research, revealing the presence of dark matter in numerous galaxies during the remaining time of her career. The growing body of evidence from their research would make the cause of dark matter indisputable.
In recognition of her contributions to astronomy, she was elected to the National Academy of Science in 1981. In 1993, she was awarded the National Medal of Science by President Bill Clinton. Although overlooked by the Nobel Committee, it has been and continues to be an inspiration to women in science. "She has been moving from job to job for over a decade, but her struggle has inspired me to keep pushing, to do what I love, to truly believe that something will work, and now I'm a scientist NASA. "  Rubin died on Christmas Day in 2016 at the age of 88. It is remembered in the solar system. Vera Rubin Ridge in the Gale Crater on Mars and the asteroid 5726 Ruby were named in her honor. Her four children inherited her curiosity for the universe, each with a doctorate in science.
"My life was an interesting journey," Rubin wrote in 2011. "I became an astronomer because I could not imagine living on earth and not trying to understand how the universe works."