He is best known for his work on the structure and evolution of the Milky Way galaxy, and for the discovery of Bok globules, which are small, densely dark clouds of interstellar gas and dust that can be seen silhouetted against brighter backgrounds.

[1] The Boks displayed such great mutual enthusiasm for explaining astronomy to the public that The Boston Globe described them in 1936 as "salesmen of the Milky Way".

[4] When he was asked by the editors of Who's Who in America to submit a statement concerning "Thoughts on My Life", he wrote, "I have been a happy astronomer for the past sixty years, wandering through the highways and byways of our beautiful Milky Way.

When asteroid 1983 Bok was named for him and his wife Priscilla, he thanked the International Astronomical Union for giving him "a little plot of land that I can retire to and live on.

He attended high school in The Hague, excelling at mathematics and science, and he also told the story that this was where he met a Scoutmaster who introduced him to the night sky while on camping trips away from the city lights.

[3] Their marriage began a close scientific collaboration that would span the next four decades, in which the Royal Astronomical Society said "it is difficult and pointless to separate his achievements from hers".

[12] This hypothesis was difficult to verify due to the observational difficulties of establishing what was happening inside a dense dark cloud that obscured all visible light emitted from within it, but after Bok's death his ideas were confirmed when analyses of near infrared observations published in 1990 confirmed that stars were being born inside Bok globules.

While there, he and Priscilla also enjoyed the opportunity to study the southern stars, including Eta Carinae which had been the subject of Bart's doctoral dissertation.

Starting in 1952 he led the efforts to fund and construct a major radio telescope facility at Harvard's Oak Ridge Observatory.

This combined approach proved to be vital in analyzing the interstellar medium, and particularly in developing an understanding of what was happening inside Bok Globules.

[1]: 540 [4] In 1957, the Boks moved to Australia, where Bart took up the position of Director at Mount Stromlo Observatory in the Australian National University (ANU) in Canberra, which he was to hold for the next nine years.

[3] However, Bok appreciated the limitations of the site of Mount Stromlo due to weather and increasing light pollution, and he initiated a site-testing program which stretched across the country.

[9] Their close relationship and the way their personalities complemented one another supported their scientific efforts: Priscilla's empathy balanced Bart's energetic and dynamic nature.

[8][17]: 608 In the subsequent editions of their book, the Boks made major changes to accommodate the rapid progress in galactic astronomy.

[15]: 111 This ability to "sell" astronomy to the public and especially to the Members of Parliament was crucial in winning support for such huge, and expensive, projects as the Anglo-Australian Observatory against competing scientific priorities.

In 1966, the Boks moved back to the US, where Bart took up the roles of Head of the Department of Astronomy at the University of Arizona and Director of Steward Observatory, posts which he held until 1970.

He was largely responsible for the construction of the 90 inches (2.3 m) telescope at the Kitt Peak National Observatory, and oversaw a doubling of the university's staff and growth in the graduate student program until by 1970 it was ranked fifth in the US, and Steward was regarded as "one of the world's premier astronomical research institutions.

[19] Priscilla suffered a stroke in 1972; her health declined in the following years, and Bok resigned his positions with the IAU and the AAS in 1974 and dedicated himself to her care.

[8] In 1975 Bok coauthored the statement Objections to Astrology, which was endorsed by 186 professional astronomers, astrophysicists, and other scientists, including nineteen winners of the Nobel Prize.