Williamina Fleming was born 1857 in the city of Dundee, where she lived until emigrating with her husband to the US in her early twenties.  

In order to support herself and her baby son after her husband left, Williamina took work as a maid for Edward Charles Pickering, the Director of Harvard College Observatory. Pickering employed Williamina as one of his low paid ‘computers’ who manually worked out calculations at the observatory. Originally hired as a slight to his male employees - Williamina soon took over the running of the ‘computers’ at the observatory and employed a women-only workforce from a diverse range of backgrounds, with and without education. 

The job involved examining photographic plates of the stars, taken from the observatory’s telescopes at night. Williamina Fleming and her colleagues would look at these pictures of the stars and work out their brightness, distance from earth and even their chemical compositions, sorting them into different classifications. The discoveries were exciting but the work was often repetitive, painstaking and poorly paid. 

Williamina alone is said to have processed 200,000 of the photographic plates during her career cataloguing over 10,000 stars including; 310 Variable Stars - stars that can be seen from earth whose brightness and appearance changes for a range of reasons, 10 Novae - Seemingly new stars that appear in the sky and then slowly fade over a short time, 52 Nebulae - Clouds of material, dust and gasses that gather between stars. Most famously she discovered a nebula shaped like a horse's head, named the Horsehead nebula.

Henrietta Swan Leavitt was born in 1868 in Massachusetts. She studied at Harvard’s Radcliffe college towards a Bachelor of Arts and whilst there became interested in Astrology, volunteering at the Harvard Observatory alongside Wiliamina Fleming and Annie Jump Cannon.
She measured the brightness of stars by studying 'variable stars' - those whose brightness changes over time. She observed that the brighter the star the longer they shone. This discovery allowed her to measure distances. She titled these pulsing stars as 'Cepheid Variables' identifying them not only in our own galaxy: the Milky Way, but in other galaxies named the Magellanic Clouds 200,000 light years away.
Even at light years away she was able to observe the length of time these stars pulsed, meaning from her research she could calculate their brightness and so determine their distance.
Her calculation was named Leavitt’s Law and was adopted as the most important way to determine distances between objects in the Universe.
By her death in 1921 at the age of 53, Leavitt had discovered more variable stars than any other astronomer before her, about half of those known today!
​Her work was pivotal to the later development of astronomy, but a proposed nomination in 1926 for the Nobel prize in physics could not be awarded posthumously.
She was however, memorialised in the naming of asteroid 5383 Leavitt as well as the Leavitt Crater on the far side of the moon.

Annie Easley was born in Birmingham, Alabama in 1933. She studied pharmacy in New Orleans but postponed her graduation after getting married.

Racist laws in her hometown meant that African American’s had to pass a test and pay a fee in order to vote in elections. Annie used her education to tutor others sitting the test - allowing more African American votes to be counted. 

In 1954 Annie moved to Cleveland, Ohio. She tried to continue with her studies in pharmacy but was not allowed to study in the state. After reading about two sisters who were working as computers at Cleveland’s Aircraft Engine Research laboratory, she joined the National Advisory Committee for Aeronautics (which later became NASA). She stayed here from 1955 for the rest of her career.

She worked as a coder on the Centaur high energy rocket booster - the engine which pushes spacecraft out of earth’s orbits. It had its first successful launch in 1963 and a variant of this engine is still used today in launching satellites that we use everyday for weather and mapping.

As part of her work as a human computer she developed code to try and understand alternative power technologies. This code contributed towards the development of solar and wind energy projects as well as the earliest hybrid-powered cars. 

While she contributed to this work and simultaneously earned her degree in Mathematics from Cleveland State University, she also worked as an Equal Employment Opportunity counselor, representing other workers who experienced discrimination for their race, gender or age across NASA. On top of all this, she somehow still had time to found the NASA Lewis Ski Club.

Mae Jemison was born in 1956 in Decatur, Alabama. Growing up she was always interested in space but noticed that none of the exclusively white-skinned astronauts she saw on television looked like her. She wondered; "what if the aliens saw them and said, are these the only people on Earth?"

As a child she would carry out scientific experiments at home which led on to her studying Chemical Engineering and African-American studies at Stanford. Mae earned a medical degree from Cornell University and worked as a GP in the USA and as a doctor in the Peace Corps in Liberia and Sierra Leone. 

She applied to NASA in response to a call out for astronauts and after a lengthy training process, Mae became the first black woman in space. In 1992, Mae orbited the earth 126 times aboard the shuttle Endeavor. During the mission Mae carried out scientific investigations on bone cells. Back down on earth, she left NASA the following year and founded her own technology research company. 

Today, she leads the 100-Year Starship programme: an initiative to send astronauts beyond our solar system within the next hundred years. The project hopes that the developments and discoveries made as part of this research will include and benefit as many people on earth as possible. 

Mae Jemison has often said that her achievements in space were helped by her love and dedication to dance. She believes that science and arts should always be connected, and that imagination is key to discovery. 

Her foundation - The Dorothy Jemison Foundation (named after her mother) - supports experimental teaching approaches and hosts The Earth We Share international science camp where young people from across the world work together on some of the planet’s most difficult and urgent questions.

Annie was born six years after Williamina in 1863. Annie’s mother had always encouraged the young Annie’s passion for stars - going so far as to build a small observatory in the attic of their Delaware home. Annie was well-educated, studying physics and astronomy at Wellesley College for Women.  Despite sudden illness causing her lifelong deafness, she returned to her studies of astronomy at Harvard’s Radcliffe College for Women, spending her spare time at the Harvard Observatory partly run by the aforementioned Williamina Fleming.

Annie Jump Cannon found a simpler way of classifying the stars, categorising them based on their temperature. She established a scale - O, B,A,F,G,K,M - of which ‘O’ is the hottest and ‘M’ the coolest. Our sun is class G!
To help astronomers remember this order she came up with the mnemonic;
‘Oh! Be A Fine Girl. Kiss Me’
This is known as the Harvard Spectral Classification System and is still to this day in official use.
Annie was appointed as the curator of Astronomical Photographs at Harvard in 1911, a position she held for 27 years.
She advocated for Astronomy worldwide, becoming the first woman to receive an honorary degree from Oxford University and in 1923 was voted one of the 12 greatest living women in America.
In 1932 Annie was awarded the Ellen Richards research prize from The Society to Aid Scientific Research by Women. She used the $2000 prize money (about $40,000 in today’s money) to establish the Annie Jump Cannon Prize for women astrologers. The prize is still awarded every year to date. 

Cecilia Payne was born in England in 1900. Encouraged by her widowed mother in her studies across arts and sciences, Cecilia won a scholarship at Cambridge University. Originally focusing on botany, physics and chemistry, she became increasingly interested in astronomy. After graduating she moved to the US, securing a position at the Harvard Observatory as a research scientist at the age of 23. 

Cecilia's Ph.D thesis 'Stellar Atmospheres' was published in 1925 - it proposed that stars were made of helium and hydrogen, a view not shared by her male colleagues.

The belief was that silicon, carbon and other common metals were the elements that the Earth, Sun and stars were made from. Cynthia’s doctorate posited that stars were made mostly from helium and up to 75% hydrogen, making it the most abundant element in the universe.

Her doctoral degree from Radcliffe College was not recognised by Harvard until 1956 as they did not grant Ph.D certificates to women, but as time passed her discoveries were widely lauded - although sometimes credited to Henry Norris Russel who had later cited her work. 

Her Ph.D thesis was subsequently hailed as 'the most brilliant Ph.D thesis ever written in astronomy'

She was the first recipient of the Annie Jump Cannon Award in 1934 and began a lecturership in Astronomy in 1938. She had three children with her husband, Russian astronomer Sergei Gaposchkin, who were often seen in the Harvard observatory as her low wages prevented them from accessing childcare.

Cecilia eventually became the Chair of the Astronomy department before her retirement in 1966. 

In 2018 the Cecilia Payne-Gaposchkin Doctoral dissertation award in Astrophysics was created in her memory. The Payne-Gaposchkin Patera on the surface of Venus is named after her.

Valentina Tereshkova was born on the 6th of March 1937. Her Belarusian family laboured on a collective farm before the early death of her father forced her family to move nearer to Moscow. Now living near an Aeroclub, Valentina grew up to become a keen parachutist, which she kept a secret from her mother. Such training made her the perfect candidate for the new Soviet Women’s space programme. At the time, cosmonauts had to parachute from their capsules seconds before they hit the ground. Valentina was selected as one of five women for the cosmonaut corps and undertook training in centrifuge tests, decompression chambers and as a fighter jet pilot.

Three of the chosen women made it through to the final stages of testing but only Valentina was chosen to make the space flight. She followed a tradition among cosmonauts of urinating on a bus tyre prior to flight -  a tradition established by Yuri Gagarin before the first human space flight.
In 1963 she became the first woman to travel into space, as part of the Vostok 3KA spacecraft programme. Of the mission, her capsule - the Vostok 6 was the last flight. As the craft took off Valentina shouted; 

“Hey sky, take off your hat. I’m on my way”

Valentina kept a flight log as she took photographs of space and earth while manually piloting the spacecraft. Her photographs of the horizon from space were later used to identify aerosol layers within the atmosphere and data collected during the mission provided better understanding of the body’s reaction to spaceflight - mainly the great deal of nausea felt! She orbited the earth 48 times over three days - more than the flight time of all 4 Americans combined.
Upon re-entry, the capsule landed off course on the Kazakhstan-Mongolia-China border and the cosmonaut was later reprimanded for joining local villagers for food before undergoing medical testing.
Valentina is to this day the only woman to pilot a solo space flight. At 84, after a career in politics for the Soviet Union and a doctorate in technical sciences she has said: “ I would enjoy flying to Mars…..this was the dream of the first cosmonauts. I wish I could realise it! I am ready to fly without coming back.”

Sara Seager was born in Toronto, Canada in 1971 and studied Mathematics and Physics at the University of Toronto. She was awarded her PhD in Astronomy from Harvard University in 1999 and currently holds a professorship at the Massachusetts Institute in Technology in both Physics and Planetary Science.

Sara Seagar’s research has focused on the search for exoplanets. Whilst all of the planets in our solar system orbit around the Sun, planets that orbit around other stars in other solar systems are called exoplanets (exo meaning outside). Looking outside of our solar system, Sara Seagar searches for planets which have similar conditions to Earth - an Earth Twin. 

The Seagar equation calculates the number of planets we can see from earth with powerful telescopes which might have gasses that support alien life. Her groundbreaking research in exoplanets has led to some people calling her an astronomical Indiana Jones. 

In 2013 Sara received the MacArthur Genius Fellowship which helped to fund her life research. Sara Seager is part of a global team who recently discovered a gas called phosphine in the atmosphere of Venus. On Earth, we find this gas in places where tiny lifeforms live. At this stage it is unknown if the gas on Venus might be a sign of alien creatures. 

What Sara Seager says motivates her work is the belief that somewhere, there's a planet just like Earth still to be discovered.