After Hours at the Royal Observatory - Exclusive Access Tour - 30 October 2025

It was the night before Halloween, and we had booked the evening at the 350-year-old Royal Observatory in Greenwich for our first exclusive access evening - what could possibly go wrong? Well, the weather for one. The only thing you could see was thick cloud with a spooky glow where the Moon just couldn’t get through.

Did that matter? Hell no! We plan for this - we’re in England, after all 😊. I arrived at 6:30pm and proceeded to the staff entrance by the Shepherd Clock, which now serves as our designated access point for these evenings due to the closure of the South Building. From there, I went to the Meridian Courtyard, where Mike, Bobby, and Richard had already assembled.

Shortly thereafter, our members began to arrive. At 7:15pm we started the evening’s activities, dividing the group into two along the Meridian Line - come on, where else would we do it given the location?

I took my group up the old spooky spiral staircase to the Great Equatorial Telescope, where we were met by Les and Gideon. I introduced them to the group, and Les kicked the talk off and walked us through some of the history of the GET. Now, I could go into detail here about what was said in the dome, but what’s said in the dome stays in the dome 😊. You’ll just have to come along one evening to find out.

Les talks about the Great Equatorial Telescope. Picture by Simon Hurst.

Meanwhile, Mike took the other group on a whistle-stop tour through the Observatory itself, starting with the Octagon Room in Flamsteed House. He talked about why the place was built back in 1675, when King Charles II decided it was about time Britain sorted out the problem of longitude once and for all. Inside the Octagon Room – Wren’s grand design, with its high ceiling and Tompion clocks swinging away – the group heard how Flamsteed made his observations and how the space later played host to everything from “computers” crunching astronomical data to the odd coroner’s court.

The two tour groups in the Octagon Room. listening to Mike's talk. Pictures by Bobby Manoo and Richard Summerfield

From there, they headed down to the Time Gallery to meet the famous Harrison clocks. Mike gave a brief run-through of Harrison’s epic forty-year struggle to perfect the marine chronometer, from the early wooden H1 to the beautifully compact H4 – the watch that finally cracked the longitude problem and changed navigation forever.

Next stop was the Meridian Building, home to not one but several meridian lines, where Halley, Bradley, and Airy each staked their claim before the world finally agreed that Greenwich would be the zero point for both time and longitude. And to finish, the group paused by the site of Flamsteed’s ill-fated Well Telescope – a bold but damp experiment that proved astronomy and underground holes don’t mix particularly well!

After swapping the groups so each had a tour and GET session, the evening closed and a minibus was waiting for our members to drive them to the park gate - how’s that for service? 😊

Thank you to Richard, Bobby and Mike, and to all our members who attended this evening.

Pictures from the evening (by Bobby Manoo, Richard Summerfield and Simon Hurst):