On the occasion of the 400th anniversary of Thomas Harriot's Moon drawings

In late 1609 Galileo Galilei made astronomical drawings of the Moon. However it would seem that he was not the first person to do so. 400 years ago today, Englishman Thomas Harriot (above)trained his lens on the Moon and after several hours later he had produced an intricate map of the Moon’s surface, showing craters, mountains and the planet’s empty “seas” (see below).

However, Harriot never saw the need to publish his work. If he had done so, he may well have had fame. “He had a nice annual pension from the Earl of Northumberland and he was just interested in the pursuit of knowledge,” said Alison McCann, assistant county archivist for the Sussex Record Office, which holds all of Harriot’s Moon drawings, made on behalf of Lord Egremont.



Harriot’s very first recording was made using hand-held device, known as the “Dutch trunke” telescope, which was only six times more powerful than the naked eye. It would have shown a small pinpoint of sky and Harriot would have had to inch the telescope across the sky, recording as he went.

By 1613 he had a telescope with a magnification of 36 times, and was able to record some of the most striking features of the solar system including Jupiter’s spot, Saturn’s rings and the dark sunspots that we now know correspond to magnetic activity on the Sun’s surface. He is also credited with the discovery of Snell’s Law, which describes the refraction of light through a lens, 20 years before Willebrord Snellius published his own theory. In addition he made important contributions to the development of algebra and wrote a treatise on navigation.

Harriot's achievements are now being recognised finally. Two of his Moon drawings, along with recordings of Jupiter and sunspots, have been unveiled at the Science Museum. Lord Rees, president of the Royal Society and Astronomer Royal, described Harriot as astronomy’s unsung hero. “It is good that his reputation is being restored,” he said.

It does seem that Harriot was a superb scientist but he hid his light under a bushel, so to speak, and so his achievements were never given the credit they were clearly due. Then again theat is nobody’s fault but his own. That Harriot made the first astronomical drawings of the Moon does not reduce Galileo’s achievements one jot.