This year, the world is celebrating the International Year of Astronomy as it commemorates the 400th anniversary of Galileo's use of a telescope to study the skies. However, a little known Englishman and Renaissance scholar named Thomas Harriot was also exploring the heavens in 1609.
Many people think Galileo invented the telescope, but that's not true. In 1608, a Dutch spectacle-maker named Hans Lipperhey is credited for inventing a device that made distant objects seem near at hand. When Galileo read about the "spyglass," he quickly made his own and turned it on the heavens.
By December of 1609, he had perfected it as a scientific instrument. Although his telescope had a small lens with poor resolution, he began making astonishing discoveries. His telescope magnified enough for him to recognize that the Milky Way was made up of thousands of stars, there are mountains on the moon, spots on the sun, and that Venus goes through phases like our moon.
Galileo long accepted Copernicus' idea that Earth and the other planets orbited the sun, but he was the first to prove it based on his observations with a telescope.
Historians have recently discovered that by July 1609 Thomas Harriot had also built a telescope, and drew images of the moon several months earlier than Galileo. Harriot's map detailed mountains, craters and lunar "seas."
Harriot was a wealthy gentleman with no desire for fame and fortune, and he had no wish to raise his profile by publishing his discoveries. Two of his friends were in the Tower of London for their involvement in the Gunpowder Plot of 1604, in which Guy Fawkes and his conspirators tried to blow up the House of Parliament. Harriot was also arrested with the conspirators, but released a short time later.
Harriot's later observations of the moons of Jupiter and the phases of Venus also validated Copernican cosmology.