In your book, you describe some of the women as “human computers.” What does this mean?

In the days long before laptops—even before mainframe computers—human beings performed all the calculations required to ascertain star positions and track the orbits of planets, moons, and comets. At Harvard, women were given the chance to do much more than calculate. They also examined photographs taken nightly by cameras attached to telescopes, from which they identified thousands of new celestial objects.

What challenges did they face back then compared to what women have now in this field?

Naturally they earned less money than men doing similar work. They needed to choose between marriage and career, since the idea of “working wives” seemed even more revolutionary than women’s winning the right to vote. They had to defend the utility of a higher education against claims that college was wasted on a woman.

How has their contribution influenced the way we study the stars?

Their system for classifying the stars made order in the cosmos, and is still in use today. One of them discovered a means for measuring distances in space. Another came to the shocking realization that the stars consisted mainly of the two lightest elements, hydrogen and helium.

What is the most surprising discovery in your research of these women’s lives?

The presence of so many female workers at the Harvard Observatory encouraged the establishment, by wealthy patronesses, of special fellowships enabling young women astronomers to spend a year there engaged in research. As a result, Harvard’s first astronomy graduate students were all women, and Harvard awarded its first astronomy PhD to a woman who later served on the faculty and chaired the astronomy department.

What qualities do all these women share in pursuit of their work?

They shared a genuine fascination for the stellar universe, a hunger to take part in astronomical studies, a pride in their own and each other’s achievements, and a great appreciation for the beauty of the night sky.