Scottish astronomer Williamina Fleming was born #OTD in 1857. She led the Harvard Computers, a team of women whose work revolutionized modern #astrophysics.🔭 +ID'd the Horsehead Nebula, 1888 +Cataloged 10,351 stars +Discovered 310 variable stars +1st discovery of a white dwarf star #WomenInSTEM

Diane Nash: one of the most brilliant, fearless & under-recognized strategists of the #CivilRights Movement. A leader of the student wing in the 1960s, her tactical brilliance & commitment to nonviolent direct action directly altered the course of American history. She was born #OTD in 1938.

#OTD in 1970, Anna Mae Hays became a brigadier general--the first woman in history of the US Armed Forces promoted to a general officer rank. Her recommendations revolutionized conditions for military women including ending the automatic discharge of married female officers who became pregnant.

Maria Reiche (b. #OTD in 1903) was a mathematician & archaeologist who dedicated >50 yrs of her life to the study & preservation of the Nazca Lines in Peru. The "Lady of the Lines" is credited with bringing these ancient geoglyphs to international attention & ensuring their protection. #WomenInSTEM

Swedish agronomist & scientist Eva Ekeblad discovered a method to make alcohol (vodka) & flour from potatoes, which led to significantly reducing Sweden's incidence of famine. First female member, Royal Swedish Academy of Sciences, 1748. She died #OTD in 1786. #WomenInSTEM

Engineer & inventor Dr. Marian Croak established the modern fundamentals of VoIP, the foundational tech that allows voice/video data to be transmitted over the internet. Her work is the backbone for services like Zoom, Skype, FaceTime & WhatsApp. #WomenInSTEM #engineering (1/2)👇

Journalist Marjory Stoneman Douglas died #OTD in 1998 at age 108. Her 1947 book, "The Everglades: River of Grass," transformed public perception of Florida's Everglades from "worthless swamp" to priceless ecosystem. Recipient, Presidential Medal of Freedom, 1993. #ecosky #WomenInSTEM #histsky

Virginia Woolf's "Mrs. Dalloway" was first published #OTD in 1925. The novel is set on a single day in London in June 1923 and is widely celebrated as a masterpiece of modernist literature for its pioneering use of stream-of-consciousness storytelling. #litsky #booksky #skybrarian

Economist Claudia Goldin won the 2023 Nobel Memorial Prize in Economic Sciences "for having advanced our understanding of women's labor market outcomes." She is the 3rd woman to win the economics Nobel & the 1st woman to win it solo. First female tenured Economics professor at Harvard. #WomeninSTEM

Danish seismologist Inge Lehmann discovered the Earth's inner core, 1936. This fundamentally changed our understanding of the Earth's interior. Her discovery is attributed in large part to her incredible ability to interpret complex seismic records by hand. She was born #OTD in 1888. #WomenInSTEM

Physicist Marguerite Perey discovered the element francium in 1939. She was the the first woman elected to the French Académie des Sciences, 1962--an honor denied to her mentor Marie Curie. She died #OTD in 1975 & is one of the 72 women whose names to be engraved on the Eiffel Tower. #WomenInSTEM

International Nurses Day is celebrated globally on May 12--the date chosen to commemorate the birth of Florence Nightingale #OTD in 1820. Nightingale is considered the founder of modern nursing & was a brilliant mathematician (first woman elected, Royal Statistical Society). #WomenInSTEM #medsky

Katharine Hepburn, The Great Kate, was born #OTD in 1907. The First Lady of Cinema holds the record for the most Academy Awards for Best Actress with 4 wins. Named by the American Film Institute as the greatest female star of Classic Hollywood Cinema, 1999. #ClassicHollywood #filmsky #FilmHistory

Polish high-altitude mountaineer Wanda Rutkiewicz was the first woman to summit K2 (2nd highest peak in the world) in 1986 & the first European woman to Summit Mt. Everest (1978). She died ~#OTD in 1992 while climbing Kangchenjunga, the 3rd highest mountain the world. #mountaineering

Dr. Maryam Mirzakhani was the first female winner of the Fields Medal, the most prestigious award in #mathematics. Today, May 12, is International Women in Mathematics Day--the day chosen specifically to honor Mirzakhani's legacy. She was born #OTD in 1977. #WomenInSTEM

British chemist Dorothy Hodgkin won the 1964 #Nobel Prize in #Chemistry for using X-ray crystallography to "see" the 3D structures of complex molecules. After 35 years of work, she solved the incredibly complex structure of insulin, 1969. She was born #OTD in 1910. #WomenInSTEM

American aviator Harriet Quimby the first woman to fly across the English Channel, 1912. Her only instruments were a hand-held compass and a watch. She was the first woman in the US to obtain a pilot's license, 1911. She was born #OTD in 1875. #aviation #AvGeek #AviationHistory

#OTD in 1978, Margaret Brewer became the first female general officer (Brigadier General) in the US Marine Corps. #USMC She had served as the Director of Women Marines (1973–1977), where she played a crucial role in integrating women more fully into the Corps & expanding their career fields.

At the time of her death, legendary aviator Jacqueline Cochran held more speed, distance & altitude records than any other pilot in history, male or female. An #aviation pioneer, she was the first woman to fly a bomber across the Atlantic & to break the sound barrier. She was born #OTD in 1906.

Engineer & 🚀Astronaut Dr. Ellen Ochoa was born #OTD in 1958. + 4 space shuttle missions,~1,000 hours in space + 1st Hispanic woman in space, 1993 + 1st Hispanic/2nd female director, NASA Johnson Space Center, 2013 + Chair, Nat'l Science Board, 2020–2022 + Presidential Medal of Freedom #WomenInSTEM

Happy Mother's Day, mom. I lost you 23 years ago yet you remain the strongest influence in my life. I am what I am because of you yet I have so much more to become and to accomplish to live up to your example. 😘

🔭 Astronomer Cecilia Payne-Gaposchkin made one of the most fundamental discoveries in the history of science: stars are made primarily of hydrogen & helium. Her 1925 PhD thesis is widely regarded as the most brilliant ever written in #astronomy. She was born #OTD in 1900. #WomenInSTEM #AstroSky

Freya Stark's travels have inspired generations of female adventurers. Stark is widely regarded as one of the most significant female explorers of the 20th century & one of the most influential travel writers in history. She died #OTD in 1993 at age 100. (1/2) #inspiration #travelsky #adventure

🔬 Elizabeth Kaweesa studies plant-derived compounds that could help combat chemotherapy resistance in ovarian cancer. On #WorldOvarianCancerDay, her story highlights the power of perseverance, mentorship & cancer research. ➡️ www.asbmb.org/asbmb-today/... #WomenInSTEM #CancerResearch #OvarianCancer

Tegla Loroupe was born #OTD in 1973. + 1st African woman to win the NYC Marathon + Women's world records: track 25km & 30km + Global spokeswoman for peace, #womensrights & #education + Organizer, 2016 Summer Olympics Refugee Team + Founder, Peace Foundation teglapeace.org/ab/#OTD#womensrights#education#Kenya #WomenInSports

#OTD in 2018, Delaware became the first US state to ban #childmarriage. Child marriage is now banned in 16 US states with the minimum marriage age at 18 w/no exceptions. Child marriage disproportionately impacts girls-->~86% of all minors married were girls & ~80% of them to adult men.

The other central person in this story was Dr. Louisa Garrett Anderson. There is so much to this story, it would make a great movie. There is a 14-minute mini-documentary called Deeds not Words: The Suffragette Surgeons of WWI. It's on YouTube. 👇

Dr. Flora Murray knew she would be told to "go home & knit” by the UK War Office if she offered to treat wounded soldiers in #WWI. So, she & other female medics went to the French & set up a hospital in a Parisian hotel. When they offered to go back to England in 1915... (1/2)👇#WomenInSTEM #histsky

Geographer Ellen Churchill Semple died #OTD in 1932. A founding member of the Assoc. of American Geographers (1904), she was its first female president, 1921. Significant contributor to the early development of the #geography discipline (US) & a leading figure in #humangeography. #WomenInSTEM

Mary Mahoney (b. #OTD in 1845): First African American to graduate from a professional nursing school (1879) & earn a nursing license in the US. + Co-founder, Nat'l Assn of Colored Graduate Nurses, 1908 + One of the first women in Boston to register to vote in 1920 (19A) #WomenInSTEM #blackhistory

Denise Albe-Fessard (d. #OTD in 2003): pioneering French neuroscientist renowned for her groundbreaking research into the central nervous system's processing of pain. + 1st President, Internat'l Association for the Study of Pain, 1975 + 1 of 72 women being engraved on the Eiffel Tower #WomenInSTEM

#OTD in 1794, Ann Radcliffe published her Gothic romance "The Mysteries of Udolpho." Known as the "Mother of the #Gothic," she helped legitimize the genre in the 1790s & pioneered "explained supernatural," where seemingly magical events are given rational explanations. #booksky #skybrarian #litsky

#OTD in 2020, Rockford Peaches pitcher Mary Pratt died at age 101. One of the first members of the Peaches, the team at the heart of the movie "A League of Their Own." A southpaw, she used her famous "controlled slingshot" to pitch a no-hitter in June 1944. I ❤️ #baseball ⚾️

Celebrating Virginia Henderson, the First Lady of Nursing, on National #NursesDay. Widely considered the most famous & influential nurse of the 20th century both in the US & worldwide. She is credited with developing a nursing theory in which she defined the role of nurses in healthcare. #MedSky

#OTD in 1935, Audrey Wurdemann won the #Pulitzer Prize for Poetry for her 1934 collection of poems titled "Bright Ambush." She is the youngest person to win the #poetry Pulitzer. She was 24. #litsky #booksky #skybrarian

Celebrating Colonel Ruby Bradley--one of the most-decorated women in US military history--on US #NursesDay. + 34 medals/citations of bravery (incl 2 Bronze Stars) for her service during #WWII & the Korean War + WWII #POW for 3 years; while imprisoned, she assisted in >230 surgeries #courage (1/2)

British archaeologist Dorothy Garrod (b. #OTD in 1892): First female Professor of Archaeology at Cambridge (1939-52), appointed 9 years before Cambridge granted women degrees. She led excavations in Palestine (1929-34) uncovering the first Neanderthal skeletons found outside of Europe. #WomenInSTEM

#OTD in 1809, Mary Dixon Kies was granted a US patent in her own name (for a method of weaving straw w/silk or thread to create hats). She may have been the first. Female inventors had to file patents under their husbands' names as women had limited legal rights to own property. #histsky #inventors

Nellie Bly was born #OTD in 1864. Departing on Nov 14, 1889 & aiming to beat the fictional record from Verne's "Around the World in Eighty Days," she completed her record-breaking journey on Jan 25, 1890. Around the world in 72 days! #adventure Her route: theportuguesetraveler.com/routes/route...

Humanitarian & actress Audrey Hepburn was born #OTD in 1929. One of a small group who won an Emmy, Grammy, Oscar & Tony award (EGOT). Devoted much of her later life to #UNICEF, working in some of the poorest areas of Africa, S. America & Asia; awarded the Presidential Medal of Freedom. #legend

Congrats to Julie K. Brown! She was awarded a #Pulitzer Prize special citation today for her groundbreaking reporting in 2017 & 2018 for the Miami Herald exposing Jeffrey Epstein's systematic abuse of young women and the justice system & powerful network of associates that protected him for years.

Congrats to Gabriela Lena Frank! Today, she won the 2026 #Pulitzer Prize for Music for her programmatic orchestral piece, "Picaflor: A Future Myth." #musicsky #orchestra #music

Congrats to Juliana Spahr! Today, she won the 2026 #Pulitzer Prize for Poetry for her book, "Ars Poeticas." #booksky #litsky #skybrarian #poetry

Congrats to Yiyun Li! She just won the 2026 #Pulitzer Prize for Memoir or Autobiography for her book, "things in nature merely grow." #booksky #litsky #skybrarian

Congrats to Amanda Vaill! She just won the 2026 #Pulitzer Prize for Biography for her book, "Pride and Pleasure: The Schuyler Sisters in an Age of Revolution." #booksky #litsky #histsky

Congrats to Jill Lapore! She just won the 2026 #Pulitzer Prize for History for her book, "We the People: A History of the U.S. Constitution." #histsky #booksky #litsky

German athlete Ulrike Nasse-Meyfarth won 2 Olympic gold medals in the high jump with a cool twist: 🥇 1972: Youngest Olympic champion ever in women's high jump, age 16 🥇 1984: Oldest Olympic champion ever (at the time) in women's high jump, age 28 She was born #OTD in 1956.

I love reading her biography Shark Lady with my students! #kidlit

It's International Firefighters' Day! #IFFD Thank you! to all #firefighters for your dedication and your sacrifices to protect us and help keep our families & communities safe. An extra special shout out to our firefighters here in #NYC.🍻 📷: Brenda Berkman, FDNY's first female firefighter

Ichthyologist Eugenie Clark--The Shark Lady--was born #OTD in 1922. A pioneer in scuba diving for research purposes, she proved sharks are capable of learning and was a world authority on Tetraodontiformes. Founded Mote Marine Lab and used her fame to drive global marine conservation. #WomenInSTEM