On a clear autumn night in 1847 Maria stood on the roof of her parent's house, focusing her telescope on a faraway star. Suddenly she realized that the faint, blurry light wasn't a star at all, but a comet. The discovery of a comet wasn't a rare event in the nineteenth century, but women astronomers were rare indeed.

In 1848, Maria became the first women member of the American Academy of Arts and Sciences, and later became a fellow of the society. She served as professor of astronomy at Vassar College from 1865 to 1888. In 1875 Mitchell was elected president of the American Association for the Advancement of Women. Mitchell died on June 28, 1889.

Throughout her career Maria encouraged young women in the same way her father had encouraged her, to be anything they wanted to be. After her death, the Maria Mitchell Astronomical Society was created as tribute to her memory. Mitchell was elected to the Hall of Fame for Great Americans in 1905.