We are coming up on 400 years now since Galileo Galilei made a discovery that changed the way we look at the world. Quick — no peeking — do you recall what it was? A. He calculated the force of gravity. B. He found the first trade route from Europe to China. C. He discovered four moons of Jupiter. D. His work with refrigeration led to the first viable version of gelato. The answer, of course, is C. His observation that four objects were orbiting Jupiter was the first empirical demonstration — very upsetting to the order of things at the time — that not everything in the heavens circled the earth. Rice University has a comprehensive site about him HERE. If you did not get the right answer off the top of your head, you are far from alone. The Royal Astronomical Society in Britain, along with several other groups, commissioned a poll…and found that people there didn’t know either. "The results show that nearly one third (29 percent) of the UK is just as likely to associate the name Galileo with wine, fashion or a famous ship before associating him with astronomy," says the RAS in a statement. "Also of concern, almost three quarters of the UK (73 per cent) credit Galileo with erroneous discoveries, such as Neptune or the black hole at the centre of our Milky Way Galaxy, or simply don’t know what he discovered — the four large satellites of Jupiter." Apparently, says the RAS, people know other historical figures better. They know that Marco Polo made it to China, that Isaac Newton quantified gravity, and when you say "Einstein" to them, they say "relativity." But Galileo…well, Galileo was more disturbing in his time. He’s given credit (sometimes disputed) for hearing about a newfangled invention called the telescope, and thinking, before anyone else, to use it for an examination of the night sky. He looked at the moon, and reported that its surface was not perfectly smooth as people had believed. He later looked at Venus and saw it changing from crescent to gibbous to full phase — further proof, he argued, that Copernicus was right about a sun-centered universe. "The Starry Messenger" (Sidereus Nuncius in the original Latin) was his lab report. Bard College has posted a translation HERE; see p. 12 for his description of the Jovian satellites. For all this he was put under house arrest and made to recant by the Catholic Church, which finally apologized in 1992. (You can find differing versions of the story HERE and HERE.) 2009, to mark 400 years since all that began, is the International Year of Astronomy, and there’s an introductory video HERE on YouTube. You may separately like to check out a podcast called 365 Days of Astronomy. But back to Galileo. "In publishing the results of this survey we are not pointing a finger," says Ian Robson, the chair of Britain’s International Year of Astronomy, "just hoping to remind the UK how one man and one telescope changed the world forever."