More than 350 people got to enjoy a special tour of the Royal Astronomical Society (RAS), mingle with bygone astronomers Caroline and John Herschel, and experience some entertaining science as an Open House day of celebration proved to be a big hit with the public.
The event took place at the Society's offices in Burlington House, Piccadilly, from 10am-5pm on Saturday 20 September.
It was part of Open City's Open House Festival, an annual celebration of London's architecture and neighbourhoods, as well as the people and communities that make them.
Visitors described the experience as "awesome" and the appearance of the Herschels – played by actors from Spectrum Drama – as "a great surprise" that "brought the history to life".
Adam Boal, Public Engagement Officer at the RAS, said: "It was great to open up our building to the public for Open House 2025.
"We have an incredible, historic building and we are always happy to share the chance to come and look inside at our public events for adults and families."
The day included a series of guided tours around RAS HQ and some fun activities for children, such as how to make a comet using dry ice.
Other learned societies based at Burlington House also took part in Open House, including the Geological Society and Linnean Society.
RAS Librarian and Archivist Dr Sian Prosser said: "For my part, it's one of the highlights of the working year to welcome hundreds of curious, interested people into the premises we've occupied for 151 years, and share with them current developments in astronomy as well as historic observations from our library and archives.
"We are grateful to Open City for organising this day, and for providing us with volunteers to help us open up the building. And working with Spectrum Drama really helps bring the history of astronomy to life!"
The RAS would like to thank everyone who came along on the day.