The telescope recently notched its 400th anniversary; in the summer of 1609 Italian scientist Galileo demonstrated his first refracting model.
Noblemen and senators followed him to the top of the Campanile bell tower in Venice. One by one they peered through the magic glass and, in awe, saw ships 80 kilometres out to sea, along with 'cattle grazing on the distant hillsides and the worshippers going in and out of their churches in the faraway towns and villages'.
Stories about astronomy rarely make headlines these days; even in technology publications the subject is neglected in favour of reports about spyware and other security concerns. If alien life forms were discovered, that might shift the spotlight somewhat. But exciting things are happening in the field.
The world's most powerful planet-searching telescope, named after the German stargazer who first stated laws of planetary motion - Johannes Kepler - was launched into an orbit around the sun on March 6 on a mission that is expected to take 31/2 years.
The Kepler telescope (right) works by measuring planetary shadows thrown against stars. It can even detect shadows cast by planets as relatively tiny as earth.
The Kepler observatory has shown promise, already shedding light on a planet outside our solar system that was discovered last year. HAT-P-7 was found to be 'tidally locked', which means it always exposes the same side to the star, just as our moon always shows the same side to the earth.
According to planetary scientist Sara Seager, of the Massachusetts Institute of Technology, in the United States, Kepler is capable of sensing 'alien earths' - planets similar to our own. That will have far-reaching consequences, says Eric Schlegel, a physics professor at the University of Texas at San Antonio. 'Finding earth-sized planets is key to the search for life elsewhere and for assessing how plentiful or rare life may be in our galaxy,' he says.
Pre-Kepler, science was able to detect Jupiter- to Neptune-sized objects. Smaller, earth-sized objects posed a much stiffer challenge.
With the data from Kepler, it ought to be possible to fathom the nature of worlds that are light years away. Science will then 'decipher their fingerprints', analysing light gathered directly from the planets or studying light that shines through their atmosphere when they pass across their stars. From there it will be possible to see if the planets under scrutiny resemble the earth, Venus or Mars, or are something totally different. Hi-tech telescopes such as Kepler may finally settle the question of whether the earth is the only hospitable planet.
We've already come quite some way from the days when seeing distant ships through a lens from a bell tower defined success.