Shapley, when director of the Harvard College Observatory and yet another Dutchman showed up at his door looking for work, is said to have called Holland ‘the place where they grow tulips and astronomers for export’. https://twitter.com/matthewjdowd/status/1323223839405387776

Perhaps it’s worth looking at why this is so, for there undoubtedly is a great roll call of Dutch astronomers. Of course, I’d like to think it’s the legacy of Christiaan #Huygens (> #DutchLight!). But most of these astronomers came along centuries later. Is it just the #bigskies?

More likely it‘s the influence of the Leiden Observatory, whose leaders have given their names to familiar features of the Solar System and beyond. For example, Jan Oort has the Oort cloud (of icy planetesimals). The Willem ‘de Sitter universe’ modelled Einsteinian curvature. . .

Adriaan van Maanen worked with Shapley at @MtWilsonObs photographing nebulae, laying the groundwork for Hubble’s expanding universe. James Van Allen ( but of descent) gives his name to the radiation belts around Earth. Gerard Kuiper is regarded as . . .

. . . the founder of modern planetary science. He studied @UniLeiden before emigrating to . Kuiper identified CO2 on Mars and methane on Huygens’s Titan. The Kuiper Belt is a ring of asteroids beyond the planets. He was also an important mentor to one Carl Sagan . . .

It’s nice to know that, while observing Mars together, Kuiper and Sagan spoke about the possible nature of extraterrestrial life just as Christiaan Huygens and his brother Constantijn had done three centuries before.

One more – recent (2007) – Dutch find is Hanny’s Voorwerp (‘voorwerp’ is Dutch for ‘object’), a weird galaxy-sized quasar made luminous by radiation from a nearby nebula. It’s named after teacher Hanny van Arkel who was taking part in a galaxy-describing citizen science project.