Ticketed Free for members

Essential Information

Location
Royal Observatory
Price Included with entry to the Royal Observatory

Stand beneath the magnificent onion dome and marvel at one of the biggest telescopes in the world.

The 28-inch Greenwich refracting telescope is the largest of its kind in the UK and the seventh largest in the world.

It was built to research double star systems and remained in use until the late 1960s. With the recent addition of a computer-aided guidance system and CCD camera, it continues to work as an excellent visual aid to observing the night sky.

The Onion dome roof was originally made from papier mâché, but now is fibreglass.

Image

Telescope facts

It took eight years to make and was a great success in the Royal Observatory’s programme of 'double star observations'.

It rests on a mount built 30 years earlier for a smaller telescope. The telescope tube is over 28 feet (8.5 metres) long and is round at each end but rectangular in the middle. This is because its mount was built for a much smaller telescope, so the middle section of the tube had to be tapered in order to fit.

Attached to the outside of the tube are smaller telescopes, used as guides to target an object or to magnify the telescope’s scales. The mount allows the telescope to be rotated on the same axis as the Earth, so it can follow a star from east to west across the sky.

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A father and son play on the Prime Meridian Line outside the historic Flamsteed House building of the Royal Observatory

Royal Observatory

  • Royal Observatory
  • Meridian Line
  • Free Museums
  • Planetarium Shows
  • Cutty Sark
Adult £16
Child £8
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A brother and sister with their back to the camera look out from the viewpoint at the top of Greenwich Park towards historic Greenwich

Royal Museums Greenwich Day Pass

  • Cutty Sark
  • Royal Observatory
  • Guaranteed entry time
Adult £25
Child £12.50
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  • Free entry
  • Priority booking
  • Membership card number required
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Advance booking essential
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National Maritime Museum

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  • Unlimited entry all year
  • Royal Observatory
  • Cutty Sark
  • Planetarium Shows
  • Special exhibitions
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Family: from £65 Family: from £75
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