Maria Mitchell

Maria Mitchell (August 1, 1818 – June 28, 1889) was an American astronomer, librarian, naturalist, and educator. She was the first woman to gain international recognition as a professional astronomer and a professor of astronomy, and also the first woman elected as a Fellow of both the American Academy of Arts and Sciences and the American Association for the Advancement of Science.

Mitchell was born on Nantucket, Massachusetts, the third of ten children. Her father, William Mitchell, was a schoolteacher and amateur astronomer, and her mother, Lydia Coleman Mitchell, worked at two libraries. Raised in the Quaker faith, Mitchell and her siblings were taught about nature and astronomy by their father, and their mother’s library jobs gave them access to a wide range of knowledge. From an early age, Mitchell showed a talent for astronomy and mathematics, and her father trained her to use instruments like chronometers, sextants, refracting telescopes, and Dolland telescopes. She often helped him with his work for local sailors and with his nightly sky observations. Because Nantucket was a major whaling port, women there were used to managing households alone for long stretches, which created a culture of relative independence and equality.

After attending Elizabeth Gardner’s small school, Mitchell went to the North Grammar school, where her father was the first principal. When she was 11, her father started his own school on Howard Street, and she served as both a student and his teaching assistant. At age 12, she helped him calculate the exact moment of a solar eclipse. After her father’s school closed, she attended Unitarian minister Cyrus Peirce’s school for young ladies until about age 16, then worked as his teaching assistant. In 1835, she opened her own school, where she developed experimental teaching methods that she later used at Vassar College. She allowed nonwhite children to attend, even though the local public school was racially segregated.

In 1836, Mitchell became the first librarian of the Nantucket Atheneum, a job she held for 20 years. The library’s limited hours let her assist her father with astronomical observations and geographical calculations for the United States Coast Survey, and to continue her own education. They worked from a small observatory on the roof of the Pacific Bank building, using a four-inch equatorial telescope from the survey. Besides searching for nebulae and double stars, they determined latitudes and longitudes by measuring star altitudes and lunar culminations and occultations. In 1843, Mitchell converted to Unitarianism, though she did not attend a Unitarian church for more than twenty years afterward. The change did not cause a rift with her family. Few of her personal documents from before 1846 survive; family members believed she destroyed many to keep them private after witnessing personal papers blown into the street during the Great Fire of 1846, and because of lingering fear of another fire.

On the night of October 1, 1847, at 10:50 pm, Mitchell discovered Comet 1847 VI (modern designation C/1847 T1) using a Dollond refracting telescope with a three-inch aperture and forty-six-inch focal length. She spotted an unknown object in a part of the sky where she had seen no activity before and concluded it was a comet. The comet became known as “Miss Mitchell’s Comet.” She published a notice of her discovery in Silliman’s Journal in January 1848 under her father’s name, and the following month submitted her calculation of the comet’s orbit, securing her claim as the original discoverer. Later that year, she was celebrated at the Seneca Falls Convention for the discovery and calculation. On October 6, 1848, King Christian VIII of Denmark awarded her a gold medal prize, established earlier by King Frederick VI to honor the first discoverer of each new telescopic comet. There was a brief dispute because Francesco de Vico had independently found the same comet two days after Mitchell but reported it to European authorities first, but Mitchell was declared the first discoverer and received the prize. Only Caroline Herschel and Maria Margarethe Kirch had previously discovered comets. The medal was inscribed with a line from Virgil’s *Georgics*: “Non Frustra Signorum Obitus Speculamur et Ortus” (Not in vain do we watch the setting and the rising of the stars). Although the award was sent by letter in 1848, Mitchell did not physically receive the medal in Nantucket until March 1849. She was the first American to receive this prize.

Mitchell’s name lives on in the Maria Mitchell Association, the Maria Mitchell Observatory, and the Maria Mitchell Aquarium.