Celebrating Thomas Harriot – World’s First Telescopic Astronomer

400 years ago English polymath Thomas Harriot became the first person to look at a celestial object through a telescope. Harriot pointed his simple “ËœDutch trunke’ telescope at the Moon on 26th July 1609, making simple drawings of our nearest astronomical neighbor from his house in Syon Park in what is now West London.

Harriot made his pioneering drawings several months before Galileo. On 26th July 2009, this pioneering work will be commemorated in Telescope 400, a public event taking place at Syon Park as part of the International Year of Astronomy (IYA2009) and funded by the Royal Astronomical Society (RAS). That day members of the public will join astronomers in a celebration of Harriot’s work.

Telescope 400 runs from 11.00 a.m. ““ 5.00 p.m. and is a day of activities for adults and children alike where you can:

“¢ See an exhibition of Harriot’s maps and drawings as well as contemporary astronomical images

“¢ Enjoy Explorer Dome – a mobile planetarium – where you can learn about the night sky

“¢ Design and launch your own water-powered rocket

“¢ Make and take home your own Star Finder and Sundial

“¢ Learn how to sketch what you see through a telescope in an “Ëœart and astronomy’ workshop

“¢ Listen to short talks marking the 40th anniversary of the Apollo 11 landing

“¢ Meet a “Ëœspaceman’ and maybe Thomas Harriot himself!

“¢ View the surface of the Sun in safety through solar telescopes under the supervision of astronomers

“¢ Watch “ËœCreate a Comet’ demonstrations

At 4 p.m. the choral group Cantamus will perform a selection of 17th Century Music in the Great Hall of Syon House.

At 4.30 p.m. a memorial plaque will be unveiled by Lord Egremont of Petworth, close to the site of Harriot’s observations 400 years ago.

From 5.30 p.m. to 8 p.m. in the evening a buffet reception will follow a lecture on Harriot’s life and work by University of Oxford historian of astronomy, Dr Allan Chapman.

THOMAS HARRIOT

Harriot lived from 1560 to 1621. He studied at St Mary’s Hall (now part of Oriel College), Oxford, achieving his BA in 1580 before becoming a mathematical teacher and companion to the explorer Sir Walter Raleigh. In the early 1590s Raleigh fell from royal favor and was imprisoned in the Tower of London.

From this time Harriot was passed to the patronage of Henry Percy, the Ninth Earl of Northumberland who was himself imprisoned as one of the Gunpowder Plotters in 1605 but continued to support Harriot in his residence at Sion (now Syon) Park, in what is now West London. Harriot became a leading force in mathematics, working on algebraic theory and corresponding with scientists in the UK and across Europe.

By 1609, Harriot had acquired his first “ËœDutch trunke’ (telescope). He turned it towards the Moon on 26 July, becoming the first person to draw an astronomical object through a telescope. The crude lunar sketch shows a rough outline of the lunar terminator (the line marking the division between night and day on the Moon) and includes a handful of features like the dark areas Mare Crisium, Mare Tranquilitatis and Mare Foecunditatis.

Harriot went on to produce further maps from 1610 to 1613. Not all of these are dated, but they show an increasing level of detail. By 1613 he had created two maps of the whole Moon, with many identifiable features such as lunar craters that crucially are depicted in their correct relative positions. The earliest telescopes of the kind used by Harriot (and Galileo) had a narrow field of view, meaning that only a small portion of the Moon could be seen at any one time and making this work all the more impressive. No better maps would be published for several decades.

Despite his innovative work, Harriot remains relatively unknown. Unlike Galileo, he did not publish his drawings. University of Oxford historian of astronomy Dr Allan Chapman attributes this to Harriot’s comfortable position as a “Ëœwell-maintained philosopher to a great and wealthy nobleman’ with a generous salary (somewhere between £120 and £600 per annum or by way of comparison several times the level of the Warden of Wadham College, Oxford). Harriot had comfortable housing and a specially provided observing chamber on top of Sion House, all of which contrasted with Galileo’s financial pressures.

Image 1:  A photograph of a purported portrait of Thomas Harriot, from Trinity College, Oxford. Image: Max Alexander / Trinity College / Science Photo Library (c) Trinity College

Image 2: The first drawing of the Moon through a telescope, dated 26th July 1609, by Thomas Harriot. This crude but historic sketch roughly delineates the terminator, the line that marks the boundary between day and night on the lunar surface. The original image is a little more than 15 cm across.  The dark patches correspond to Mare Crisium (at the top), Mare Tranquilitatis and Mare Foecunditatis. Image: (c) Lord Egremont

Image 3: Thomas Harriot’s map of the whole Moon. This image accurately depicts many lunar features including the principal Maria (lunar ‘seas’ – actually lava-filled basins) and craters. Labeled features include Mare Crisium (’18’) on the right hand side and the craters Copernicus (‘b’) and Kepler (‘c’) in the upper left of the disk. Image: (c) Lord Egremont

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