THIS WEBSITE was created to publicise the achievements of Thomas Harriot and to cover the Telescope400 event. Although IYA2009 (see logo, left) is now over, this site will be maintained. There is much information here, including our biography of Thomas Harriot and also information added in March 2015 about the two replica telescopes that the team had made for the event.

TELESCOPE 400 RAN, VERY SUCCESSFULLY, ON SUNDAY 26th JULY 2009. You can see a picture of the unveiling of the Thomas Harriot Memorial below. More pictures are in the Photo Gallery. A short report is available under the link Account of the day and a copy of the A&G article on Telescope400 (Oct 2009) is available by clicking here. If you need information please CONTACT US.

NEWS: Press coverage about Thomas Harriot during 2009 has been collected in our NEWS page.

Syon Park: Sunday 26th July 2009

This event included the installation of a plaque to commemorate Thomas Harriot. Below is a picture of Lord Egremont performing the unveiling. (Credit: Max Alexander).

Lord Egremont unveils the plaque to Thomas Harriot You can see a detailed picture of the memorial plaque by clicking here. This may take a few seconds to download.


Is this Thomas Harriot?

Four hundred years ago, an Englishman named Thomas Harriot turned a telescope on the Moon and marvelled at its rugged, cratered surface. The drawing he made that night is the oldest known depiction of a celestial object as seen through a telescope, beating Galileo by four months.

  • Telescope400 celebrated the 400th anniversary of Harriot’s achievement at an astronomically themed day for space enthusiasts young and old on the very site where Harriot made his observations – Syon Park, West London. Full details of the event are here
  • Open to all and suitable for all ages, the event was held in the grounds and buildings of Syon Park    Click here for maps
  • Exciting and interesting activities ran for all the family: eg make a sundial, win a telescope!
  • A memorial to record Harriot's achievements was unveiled by Lord Egremont
  • The Quatercentenary Lecture and Reception was given by Dr Allan Chapman - Details here.
  • Those attending paid only the normal admission charge to Syon House and Gardens, all activities (except the planetarium and the Harriot Lecture) were free.


  • Exhibitions (including pictures, early telescopes and archive material)
  • Demonstrations (solar telescopes)
  • Planetarium (Star Dome)
  • Competitions (build a water rocket)
  • Things to make and take home
  • Talks

Click the links About the day or Detailed Programme for more information.

Click here to see our YouTube Commercial.

Who was Thomas Harriot?

On July 26th 1609, several months before Galileo, an English scientist, Thomas Harriot, carried out the first observations and drawings of the Moon made using a telescope at his residence in the grounds of Syon House, West London.

Syon House
Syon House, Brentford

There is very little public recognition of Thomas Harriot in the UK and no lasting memorial to his very considerable achievements in maths, physics, engineering as well as astronomy.

He collaborated with some of the most brilliant scientists of his time. He was a close friend and in the service of Sir Walter Raleigh, with whom he sailed to Virginia as a scientist/explorer. His lunar observations were remarkable for the time. His very detailed observations and drawings of the Sun and sunspots may also have been the first. He also recorded the motions of Jupiter’s satellites. Read this biography of Harriot, specially written for this event by Dr Allan Chapman of Wadham College, Oxford.


Sponsor: We are grateful for sponsorship from the Royal Astronomical Society.


  • Images of Thomas Harriot's drawings © Lord Egremont / West Sussex Archives. - we are grateful for permission to use these. Reproduction requires permission
  • Trinity College (Oxford) Portrait © Max Alexander. Reproduction requires permission. Contact via or
  • "Harriot's Moone Catalogue" (HMC)" © Geoff Burt
  • Telescope400 is run by the UK National Astronomy Week team - in existence since 1981
  • Web Site by: Brendan Blake / Edward Morgan
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