Best Royal Observatory Greenwich events for its 350th anniversary

The Royal Observatory Greenwich was established by King Charles II on 22 June 1675. Now, 350 years on, this institution that has played a key role in navigation, space exploration and timekeeping is celebrating with a year-long series of events.

Jonny Payne speaks to the curators for their top tips on what to see and do during 2025.

When is the 350th anniversary of the Royal Observatory Greenwich?

Although events are running throughout the year, the official 350th anniversary of the Royal Observatory Greenwich is on 22 June 2025.

How was the Royal Observatory’s 350th anniversary events series created?

Louise Devoy, Senior Curator at the Royal Observatory says it’s taken a year to organise the wide-ranging series of events. “We wanted to create a broad offer that appeals to many different audiences,” she says. “We decided to tie in our anniversary events to our long-standing events to make it easier to schedule, plus it’s a good way to connect with our existing audiences, as well as engage with new ones.”

Louise mentions the series is based around “three key milestones in the Observatory’s founding year”. These being the Royal Warrant appointing John Flamsteed as the first [King’s] Astronomical Observator (March 1675); the Royal Warrant appointing Christopher Wren as architect of Britain’s first state-funded, purpose-built scientific institution (June 1675); and the laying of the foundation stone (August 1675).

The calendar of events also places the observatory’s present-day work under the microscope (or should that be telescope?). Tania de Sales Marques, Senior Astronomy Manager, Participation and Engagement, adds: “We planned a year of events that would celebrate the rich heritage of the site and highlight the work we do today.”

So, what are the highlights?

Both curators point to a planetarium lecture on Pioneering Women in Observatories, 1880-1950 as being a highlight of the series so far. Louise says, “it was a real privilege to have guest speakers from Australia and the US, who gave us fascinating insights into the varying experiences of women astronomical computers at different observatories around the globe.”

But there’s plenty more to come…

“Looking ahead, I'm very excited by a day of Moon-themed events that will be held on the 4 October, bringing science, art, history and culture together,” Tania says.

She adds: “I think all the events are quite unique, as they are different from our usual offer; for example, having a heritage focus or the format of the event. It's been great so far to see people respond positively to the programme.”

What Royal Observatory Greenwich events are coming soon?

Tania explains: “From August onwards, the focus of the season will shift to astronomy and how astronomers know what they know.”

She mentions there’s also lots for kids to enjoy – “for families we will host a few talks, such as an Evening of Astrophotography at the start of August and some Meet the Author sessions in the autumn. “In addition to our regular offer, we will have a new planetarium show in August that goes back in time to see the skies of 1675, a science fiction event and a Moon festival in October. There is also solar observing happening during weekends until the end of the summer, weather permitting.”

Louise explains how the new The Sky Tonight 1675 planetarium show has been created specifically to celebrate the anniversary: “Our planetarium can show the night sky for any time and location, so in this show we will be using that to discuss how our knowledge of celestial objects has changed in the last 350 years, and travel back in time to see how the sky looked from here in Greenwich in 1675.

“Each showing will vary, depending on the presenter’s personal style and interests, as well as what happens to be visible in the sky that night – this could be anything from constellations to meteor showers!”

Keep an eye out for the latest events on Royal Observatory Greenwich’s website.

What will I learn?

Expect to learn more about the history of the observatory, from its key discoveries and observations to the pioneering people and groundbreaking technology of its day. “We’re all familiar with the Royal Observatory’s fundamental role in creating Greenwich Mean Time (GMT) and the Prime Meridian of the World (0° longitude) but many people don’t realise that the Observatory did more than just astronomy for timekeeping and navigation,” says Louise.

“From 1840, astronomers at the Observatory started to make daily measurements of the weather and the Earth’s magnetic field to provide more data for the government and other scientists. A few decades later, they also started to take daily photographs of the Sun using special telescopes (photoheliographs) that had originally been developed for expeditions to the Pacific to view the Transit of Venus in 1874.

“It was an exciting period of change for the Observatory with new instruments, buildings, technologies and staff, including women.”

Can I still get involved if I can’t make it to the events?

There are regular live streams of sessions taking place during the year, so you needn’t miss out on all the fun. Louise explains: “generally, we tend to have a livestream when there's a significant astronomical event, such as the partial solar eclipse in March.

“Our astronomers set up the telescopes and create the content for the livestream and we try to balance the show, so it's not only informative but also interesting and accessible to a wider public.”

What are the curators’ top tips for visiting the Royal Observatory Greenwich?

Aside from the special series of events in 2025, there’s plenty to see at the Royal Observatory Greenwich, spanning science, space and time.

Favourite thing to see? For Louise it’s the Time Ball, a daily time signal on the roof of Flamsteed House that drops at precisely at 1pm. “It’s a simple action but it reminds us that we still need to coordinate time for our work, travel and communications,” she says.

“It’s also a reminder of the global significance of the Royal Observatory: mariners originally used this time signal in the 1800s to check their chronometers before heading out to sea. “These accurate sea clocks were used for charting the seas which, in turn, made Greenwich an essential place of reference for time and location. It’s just one time ball, but it has so many stories and connections!”

Tania loves the planetarium shows and seeing “how the public responds to being in that space. It's almost magical!”

How can I get Royal Observatory Greenwich tickets?

Explore this historic site for yourself and get involved in one-off and unique anniversary events throughout the year – buy your tickets for the Royal Observatory now (some events might require separate tickets). Or delve deep into our galaxy and beyond with tickets to a show at the Peter Harrison Planetarium.

If you’re keen to see more in Greenwich, combine a visit to the Royal Observatory with time exploring historic ship, Cutty Sark with a Royal Observatory Day Pass.