Now considered the founder of modern astronomy, she could not get even get her Bachelor's degree in 1919 because Cambridge did not confer degrees to women. She travelled to US to join Harvard because in England she could only become a teacher since she was a woman.

 

 

She showed how to decode the complicated spectra of starlight in order to learn the relative amounts of the chemical elements in the stars. She discovered surprisingly, that the Sun and the other stars are composed almost entirely of hydrogen and helium, the two lightest elements.

 

It is because of her that we know what distant stars and planets are made of, even before setting our foot on them or sending probes. This makes our space missions more predictable and less risky and our knowledge about the universe more complete. To know that the stars acted as atoms factory we needed to know that they were only made of hydrogen and helium, the latter being a byproduct of fusion.