Essential Information

Type Experiences
Royal Observatory
Date and Times Saturdays and Sundays
Prices Included with Royal Observatory admission

Free entry for Members. Not a member? Join now

Get hands-on with a telescope, explore the surface of Mars, try your hand at using a sextant and see the invisible at the Royal Observatory Greenwich with our weekend interactive Observatory Unlocked sessions.

Every weekend our space-tastic team of Observatory Explainers will be around the site, delivering live science demonstrations and astronomy sessions for all ages.

All activities are included with entry to the Royal Observatory, and you can drop in any time to sessions that are running. Check out the highlights below for a taste of what's on offer.

Whether you're searching for answers about life in the Universe or are just curious about what it's like to look through a telescope, head for the Royal Observatory.

Need to know
  • Sessions typically run on Saturdays and Sundays between 11am and 2.30pm.
  • Activities will vary depending on weather, time of year and availability - see below for what's currently on offer.
  • Suitable for all ages unless specified.
  • All activities are free with entry to the Royal Observatory. The Young Astronomers workshop is also open to anyone with Planetarium show tickets

Plan your visit

Find more things to do at the Royal Observatory


Astrophotography - See The Invisible

With telescopes across the Earth and above the clouds, astronomers have been able to produce beautiful images of the Universe. These images contain a wealth of information and, by piecing it all together, astronomers have mapped the stars, observed distant supernovae and looked back in time to the earliest moments in the Universe.

But did you know, some of the light those telescopes see is completely invisible to the human eye, in types of light we simply can't see?

In this interactive drop-in session, learn how astronomers create stunning images of the cosmos in types of light across the rainbow and beyond, and ask our Explainers all of your burning questions about space and astronomy.

Find us in the Octagon room of Flamsteed House, all included in your ticket to the Royal Observatory.



Join a Young Astronomers workshop

How big is the Universe? Why is Pluto not a planet anymore? These drop-in family workshops are your chance to ask everything you've ever wanted to know about astronomy, and get stuck into a range of activities themed around space science and exploration.

Held inside the learning spaces at the top of the Astronomy Centre, these sessions are free for both Royal Observatory visitors and Planetarium ticketholders. Just ask staff for directions when you arrive.

Suitable for families with children aged 4-11.


Experiment with historic tools and technology

Enjoy drop-in activities led by volunteers at the Royal Observatory. Learn more about the iconic Time Ball and the history of the Royal Observatory, or take part in exciting demos showing how a compass or a camera obscura works. For exact timings, listen out for announcements on the day.

Visit the Royal Observatory

Home of Greenwich Mean Time (GMT), the Prime Meridian of the world and London’s only Planetarium

Choose your tickets

All activities are free with tickets to the Royal Observatory Greenwich. Visitors to the Planetarium can also drop in to the Young Astronomers workshop before or after their show.

Royal Observatory

  • Walk the Prime Meridian line
  • See the best view in London
  • Guaranteed entry time
  • Audio guide included
  • Planetarium shows not included
Adult £20
Child £10

Become a Member

  • Unlimited entry all year
  • Royal Observatory
  • Cutty Sark
  • Planetarium Shows
  • Special exhibitions
Direct Debit One-off
Individual: £50 Individual: £60
Family: from £60 Family: from £70