4 Women Astronomers Who Blazed a Trail to the Future of Women in Science

[Editor’s Note: This article has been adapted from a series published in 2017 by SpaceRip, MagellanTV’s sister channel on YouTube.]

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Today, women are increasingly prominent in the field of astronomy, but that has not always been the case. In fact, leading organizations such as the Royal Astronomical Society long resisted admitting women to membership, and professional opportunities for women were limited. Let’s meet four pioneering women of astronomy whose persistence and signal contributions helped clear the way for female successors in the profession.

Galileo, Cassini, Hubble, Kepler – four giants of astronomy whose namesake spacecraft have deepened our understanding of the universe. No one doubts the importance of these men in the history of astronomy, but isn’t it telling that, when you think about it, not a single spacecraft comes to mind that is named after any of their female colleagues?

In the 21st century, the number of women astronomers, astrophysicists, astrobiologists, and cosmologists has grown, but fair-minded observers would agree that there remains much progress to be made. So, in a modest attempt to balance the scale, let’s take a look at the lives and signal accomplishments of four exemplary women astronomers who, we can hope, will one day loan their names to spacecraft that extend humankind’s knowledge of the heavens.

Caroline Herschel: Polymath Astronomer Unjustly Outshone by Her Brother

In 1786, a diminutive woman peered through a rather large (for the time) telescope and saw a mysterious, long-tailed object moving through the night sky over England – Caroline Lucretia Herschel had discovered her first comet. To his credit, her better-known brother, William Herschel, referred to the object as “My Sister’s Comet” when he recorded it in his notebook. But when the Royal Family learned of Caroline’s discovery, it was her brother who was summoned to Windsor Castle to explain and demonstrate it.

Born in Germany, Caroline emigrated to England, in 1772, to join her brothers William and Alexander. She and her siblings had had little formal education, but William had established himself in Bath, England, as a musician and composer. Caroline learned to play the harpsichord, composed scores, and became a vocalist of sufficient notoriety to receive invitations to sing at major music festivals of the era. 

Out from Under Her Brother’s Shadow

Over time, the Herschels’ interests turned increasingly to astronomy. William became court astronomer to King George III, and Caroline was generally relegated to assisting him with the fabrication of telescopes and recording his observations. “I did nothing for my brother but what a well-trained puppy dog would have done, that is to say, I did what he commanded me,” she wrote in her memoir.  Emily Brontë couldn’t have said it better.

Eventually, however, Caroline came into her own as an astronomer. By 1797, she had identified eight comets, discovered an open cluster and 14 new nebulae, independently confirmed the Messier 110 nebula (aka NGC 205), and catalogued 560 more. In 1787, Caroline became the first woman to earn a salary for her contributions to science when she was granted an annual stipend of £50 by King George III.

Messier 110 (Photo credit: Wikiwand)

Back into the Shadow

The more things changed, though, the more they remained the same: Despite her independent accomplishments and rising prominence, when Philosophical Transactions of the Royal Society A was published, in 1802, Caroline’s catalogue of more than 500 newly discovered nebulae and clusters was attributed to . . . William Herschel.

In 2009, the European Space Agency launched the Herschel Space Observatory. It was named for William Herschel, not his distinguished sister.

However, later in life, Caroline received numerous awards and commendations from all over Europe in recognition of her well-earned contributions to astronomy. In 1828, she was the first woman to receive the Royal Astronomical Society’s gold medal, and she was made an honorary member of the Society in 1835. She died in Hannover, Germany, in 1848.

Mary Somerville: ‘The Queen of 19th Century Science’

As attested by Caroline Herschel’s experience with her catalogue of comets, 19th century astronomy was not exactly a progressive force in support of the equality of women. The Royal Astronomical Society was founded in London, in 1820, but restricted its formal membership to men until 1915. However, even such an archaic policy was sometimes bent just a little to admit high-achieving female astronomers from time to time, including the first two such women, Caroline Herschel and Mary Somerville, who were made honorary members of the Society in 1835.

Not So Humble Beginnings

Unlike Herschel, who came from a humble background in Germany, Somerville was born into affluence as a member of the distinguished Fairfax family from the Scottish Borders. She was encouraged in her education (albeit not with the enthusiastic support well-bred boys typically received) and demonstrated a keen thirst for knowledge from an early age. Under tutors, she studied Latin, mathematics, astronomy, geography, and art.

Following a rather typical path for a young woman of her station in life, Mary attended gala social events, concerts, and the theater, but, she wrote, “I never lost sight of the main object of my life, which was to prosecute my studies.” She married (reluctantly, some accounts say) the wealthy but overbearing Samuel Greig, a captain in the Russian Navy, when she was 24 years old. Greig was not, it seems, a particularly enlightened gentleman when it came to his wife’s continuing intellectual development. She wrote, “He had a very low opinion of the capacity of my sex, and had neither knowledge of, nor interest in, science of any kind.” Fortuitously for Mary, as it turned out, he died after only three years of marriage, in 1807.

Taking Her Place among the Royalty of Science

With Greig out of the picture, Mary had the means and freedom to pursue her true interests – a pursuit she took up with gusto. Encouraged by Professor John Playfair (yes, that was his name) of the University of Edinburgh and by her far more supportive second husband, Dr. William Somerville, she immersed herself in the physical sciences, including astronomy. Mary published papers and several books, and translated Pierre-Simon Laplace’s Mécanique Céleste (under the title The Mechanism of the Heavens).

Somerville’s Physical Geography, published in 1848, was the first textbook on the subject written in English and was in common use as late as the early 20th century.

Among Somerville’s more notable contributions to astronomical inquiries of the mid-19th century was her informed conjecture (in her book On the Connection of the Physical Sciences) concerning a then-hypothetical planet “perturbing” the orbit of Uranus. She was not alone in her speculation about the “unseen planet,” but, in 1842, she was among the first to publish her views on the possibility. Four years later, Neptune was discovered by Johann Gottfried Galle, based on calculations by John Couch Adams and Urbaine Le Verrier.

Somerville’s calculations helped point the way to the  planet Neptune. (Image credit:  NASA)

In 1838, Mary and William Somerville moved to Italy. She died in Naples, in 1872. Before her passing, Somerville received numerous honors and was elected to a bevy of scientific societies in Europe and America. At the University of Oxford, Somerville College is named after her, as are an island in the Barrow Strait, a crater on the Moon, and an asteroid. In February 2016, Somerville was chosen to appear on the new Scottish £10 banknote. And, on February 2, 2020, she was celebrated with one of this century’s loftiest honors: a Google Doodle.

Maria Mitchell: Astronomer and Women’s Educator

In the mid-19th century, there were few places better than the island of Nantucket from which to observe the heavens. On a cool night in October 1847, Maria Mitchell took her place in the observatory her father had built atop the Pacific National Bank and peered through a small telescope to discover something no one had seen previously: a rather blurry object that would soon be named “Miss Mitchell’s Comet” or, more formally, C/1847 T1.

Such a discovery was bound to gain attention. Not only was the comet named for Maria (pronounced Ma-RYE-uh), but she was awarded a gold medal by the astronomy-loving King of Denmark. Perhaps more impressive was her election to the American Academy of Arts and Sciences the following year – the first woman to earn the distinction and the only female member for almost a century after. Less impressive, but telling, was the salutation “Sir” on AAAS’s certificate of election.

Maria Mitchell (Image Credit:  Wikimedia Commons)

Precocity as Precursor to Profession

Nantucket was a prosperous whaling center when Maria was born, in 1818, into a prominent Quaker family. William Mitchell, her father, was a banker, teacher, and astronomer who insisted that his daughter receive an education equal to that afforded to boys. Maria was a precocious student and, at the age of only 17, established her own school to teach science and mathematics to girls.

In 1835, Mitchell accepted a job as librarian of the Nantucket Atheneum. She was a voracious reader and spent most of her daylight free-time reading as many of the books under her care as possible. At night, she gazed at the stars from her father’s bank-roof observatory.

Maria’s Career Takes Flight

Her discovery of “Miss Mitchell’s Comet” launched Maria’s professional career as an astronomer. Within a very few years, she was elected to the American Association for the Advancement of Science and the equally prestigious American Philosophical Society. She also became (so far as is known) the first woman employed in a professional capacity by the federal government when, in 1849, she began earning a $300 per year salary from the U.S. Coast Survey for her services as a “celestial observer.”

In 1856, Mitchell left her position at the Atheneum to travel. Late in the decade, she decamped to Europe for a year of study and meetings with prominent scientists, including Mary Somerville and Sir John Herschel, nephew of Caroline and William Herschel.

Professor Mitchell Finds a Home

Mitchell continued her astronomical studies during the American Civil War, but she was also a fervent abolitionist who refused to wear clothing made of cotton produced in the southern states. And, she had a lifelong dedication to the advancement of women’s education. As it happened, the war coincided with a transformation of education for girls and women in America, including the establishment of new women’s colleges in the Northeast.

Vassar College was founded in Poughkeepsie, New York, in 1861, and its first building was an observatory. How appropriate then that Matthew Vassar should have recruited Maria Mitchell to become a professor of astronomy and the college’s first female faculty member. She arrived there, in 1865, with her widowed father, and the two moved right in to the newly completed Vassar Observatory.

 Vassar Observatory (Photo Credit:  Vassar College)

Vassar’s Iconic Educator

“Mitchell’s dome,” as it was sometimes called, was equipped with a 12-inch telescope. It was designed to act as a classroom, a gathering place for special events, and a residence. Mitchell was a devoted and somewhat iconoclastic teacher who developed strong bonds with her students. At a time when most college studies were restricted to daytime classrooms, she brought her students into the dome for nocturnal observations of the stars and planets. To broaden their learning experiences, she would lead them on field trips to observe astronomical events such as solar eclipses in places as far away as Iowa and Colorado.

“We especially need imagination in science.  It is not all mathematics, nor all logic, but it is somewhat beauty and poetry.” –Maria Mitchell

Mitchell was a central figure on the Vassar faculty for 23 years. Several of her students went on to successful careers in astronomy, including Antonia Maury, Mary Whitney, and Christine Ladd Franklin. When she announced her retirement, in 1888, colleagues, alumnae, and students begged her to continue in residence at Vassar, but she chose to return to Massachusetts to live with family in the city of Lynn. She died the next year and was interred in Prospect Hill Cemetery on Nantucket.

Annie Jump Cannon: Bringing Astronomy into the 20th Century

By the end of the 19th century, myriad stars of the night sky had been identified. Edward C. Pickering, director of the Harvard College Observatory, recognized the need to organize and map the hundreds of thousands of stars according to their photographic magnitude. In 1896, he hired a precocious young woman named Annie Jump Cannon to assist him, jump starting, as it were, the career of one of America’s foremost women astronomers.

Annie Jump Cannon (Photo credit:  Wikimedia Commons)

An American Girl

The daughter of a Delaware shipbuilder and politician, Cannon enjoyed a conventional education for American children of the time – or at least those from prosperous families. Her mother taught her the constellations and encouraged her to pursue studies in mathematics and the sciences. She was an outstanding student at Wilmington Conference Academy (now Wesley College), in Dover, and was admitted to Wellesley College, from which she graduated with a degree in physics, in 1884.

After college, Annie became highly skilled in photography, a craft that would be of great use in her later career as an astronomer. A number of her photos from a sojourn in Spain were published in a pamphlet entitled “In the Footsteps of Columbus” that was distributed at Chicago’s Columbian Exposition, in 1893. 

After her mother died, in 1894, Cannon was hired to the faculty of Wellesley as a physics instructor. She took the opportunity also to enroll as a special student at Radcliffe College, which gave her access to Harvard University’s superior telescope. Soon, Edward Pickering knocked on her door, and her exemplary career was launched.

The Diplomatic Astronomer

When Annie was brought on as one of “Pickering’s Women” at the Harvard Observatory, she set to work helping to complete the Henry Draper Catalogue of over 200,000 stars. Her particular area of focus in the project was stars of the Southern Hemisphere. Not only did she have a remarkable aptitude for quickly examining photographic plates (identifying as many as three stars per minute), but she also demonstrated an invaluable talent for negotiating solutions to disputes regarding methods of classification for the Draper Catalogue. 

“Pickering’s Women” at the Harvard Observatory (Photo credit:  Wikimedia Commons)

Cannon’s diplomatic efforts led to the adoption of a standardized classification system. Two of her Harvard Observatory colleagues, Williamina Fleming and Antonia Maury had devised separate systems (one alphabetical and the other Roman numeric) for classifying stellar spectra. Cannon combined and simplified the two approaches into a single system in which the spectra were recognized as representing stellar temperatures. Her system was first used in a catalogue of 1,112 stars published in 1901; the system is still in use by astronomers today.

Over more than 40 years as an astronomer, Cannon put her diplomatic skills to use many times. She also classified approximately 350,000 stars (more than any of her colleagues) and is credited with the discovery of over 300 variable stars, five novae, and one spectroscopic binary. 

The Well-Honored Professor

As Cannon’s contributions to astronomy piled one upon another over decades, so did the recognition she received from astronomical organizations and academic institutions. She was the first woman to receive an honorary degree from the University of Oxford, in 1925, and the first female officer of the American Astronomical Society. In 1931, Cannon was awarded the Henry Draper Medal by the National Academy of Sciences. Harvard finally appointed her to its senior faculty when she was named the William Cranch Bond Professor of Astronomy, in 1938, three years before she died.

Perhaps Cannon’s most enduring legacy stems from her willingness to act as a model for many women astronomers and her determination to help them gain greater acceptance in the field. In 1933, the American Astronomical Society established the Annie Jump Cannon Award to honor North American women for their contributions to the study of the stars. The Cannon Award has been received by 43 women, to date, and remains one of the most prestigious such prizes in astronomy.

Women Astronomers Setting a Course to the Future

Herschel, Somerville, Mitchell, Cannon – four trailblazing women astronomers whose names may one day be attached to space rovers or transports or telescopes that everyone will recognize, not just the nerdy aficionados of space exploration. But, even without having claimed those worldly distinctions (at least not yet), these women were models for the brainy and persistent female astronomers who are making their marks at space agencies and leading research universities around the world in the 21st century.

Women like Carolyn Porco who, since the 1980s, has been a leading imaging scientist on NASA missions exploring the Solar System; Jocelyn Bell Burnell who was first to observe a spinning neutron star, or pulsar, but was somehow overlooked when the Nobel Prize in Physics for the discovery was awarded to male colleagues in 1974; and Yale University’s Debra Fischer who, with colleagues, has discovered hundreds of exoplanets beyond the Solar System. 

These and many other women are clearing the path for future generations of female astronomers. Who knows what wonders of the heavens they will discover?