Women With Impact: Lunar Craters Named After Women

The International Astronomical Union is the world’s foremost authority on the naming of astronomical objects, including the Moon and its features. There are various systems and protocols for naming these objects.

For example, the craters on Pluto are named after scientists who significantly contributed to the study of Pluto. There are more unusual themes, like craters on the asteroid “Eros” which are named after figures like Casanova, Lolita, and Madame Bovary, following an obvious theme. All the features on the planet Venus are named after women. Craters over 20km wide are named after deceased women who made significant contributions to their field, and those less than 20km are given generic women’s names. Other features are named after goddesses and other female mythological figures.

Despite Venus being reserved for them, women are seriously underrepresented on what many would agree is our night sky’s most impressive sight: the Moon. The sheer size it occupies in the night sky sets the Moon apart from an object like Venus and each named feature on the Moon carries a significance that you don’t get with other astronomical objects. There are over 1600 lunar craters named after humans yet only 33 of these are named after women.

Hypatia of Alexandria, who lived between 355 and 370-415 is the earliest woman in history with a crater named after her. She was one of the first known women to have made major contributions to the study of astronomy, math, and philosophy. Her father, Theon, was also a scholar and the last member of the Museum of Alexandria (connected to the Library of Alexandria) before it was destroyed. Book III of Theon’s version of Ptolemy’s Almagest established the Earth-centric model for the universe that wouldn’t be overturned until the time of Copernicus and Galileo. Many scholars today believe this was actually the work of Hypatia. Aside from astronomy and math, Hypatia was a well known philosopher and regularly gave public lectures to large crowds. This unfortunately led to her death as she was executed for preaching non-christian philosophy.

Dorothy Vaughan (1910-2008) is the most recent woman to have a lunar crater named after her. She was hired by the National Advisory Committee on Aeronautics (which later became NASA) in 1943. They didn’t originally hire African Americans but changed the rule during WWII due to account for the increased workload that the war effort demanded. She worked in the segregated West Area Computing Unit. Dorothy Vaughan was quickly promoted, becoming head of the West Area Computing Unit from 1949 until 1958, becoming the first African American to have a managerial role in the organization. When NACA transitioned to become NASA in 1958 she made the move and became an expert in FORTRAN programming. Beyond her technical skills Dorothy Vaughan was described as a steadfast advocate for the people she worked with. Just like Hypatia of Alexandria, Dorothy Vaughan made a huge impact in her field despite facing adversity at every turn.

In the time between Hypatia and Dorothy Vaughan there have been a number of notable women whose careers and accomplishments have been recognized with a lunar namesake.

Take Annie Jump Cannon (1863-1941) as an example. She developed the Harvard Spectral System. She was known for her speed at classifying stars and was credited with classifying 5,000 stars per month from 1911 to 1915. She continued on to catalogue about 350,000 stars over her lifetime. She was also a prominent advocate in the women’s suffrage movement. She had a lunar crater named after her in 1964, and you can likely see it with a backyard telescope. It’s called “Cannon” and it’s located near the east-northeastern limb of the Moon’s near side. It lies just to the northwest of the Mare Marginis, and south-southeast of the crater Plutarch.

And there is Nicole-Reine Lepaute (1723-1788), who was an astronomer and mathematician in Luxemburg. She not only has a lunar crater named after her but an asteroid as well. She did calculations for a book called Treatise of Clockmaking with her husband and another scientist named Jerome Lalande. She collaborated again with Lalande and another scientist to calculate when Halley’s Comet would return, and her prediction was accurate to within a couple of days, a major improvement on the 2 year range Edmund Halley himself was able to produce. She did calculations for Lalande’s Knowledge of the times and calculated the exact date and time of the solar eclipse in 1764. Her work went uncredited for most of her career despite colleagues like Lalande praising her brilliance and contributions to the work. Her lunar crater is located along the western edge of the Palus Epidemiarum, a minor lunar mare in the southwestern part of the Moon's near side.

It goes without saying that the number of women with lunar craters named after them doesn’t reflect the number of women deserving of that honour. Instead, it highlights the fact that throughout history women’s contributions and accomplishments have gone uncredited or been stolen. This is evident in the story of Nicole-Reine Lepaute and many others.

For the complete list of lunar craters named after women, MIT has it documented here: https://web.mit.edu/tripathi/www/lunar_women.html.