Image credit: NASA/Jack Pfaller

2009 is being celebrated for being 400 years since Galileo demonstrated his telescope, and discovered the four largest moons of Jupiter. The turn of the century was a huge time in the scientific world quite apart from Galileo Galilei. While Europe, especially Italy was struggling to break out from the grip of the inquisition, the ’scientific method’ was starting to take off, especially in England with the birth of the Royal Society. By ’scientific method’ I am referring to what any high school science student would recognise now, but was revolutionary back then – the postulation of a hypothesis, and experimentation to prove or disprove it. Since Aristotelian times, the ‘natural philosophy’ was just that – a branch of philosophy. Philosophers would argue a hypothesis based on its merits in a naturally ordered universe. Actually experimenting was anathema.

In 1600, Johannes Kepler met Tycho Brahe. Working for Brahe at his new observatory, Kepler used physical observations to progress his mathematical models, and to underpin his laws of planetary motion. His work was itself one of the foundations of Newton’s theories of gravitation. As well as an astronomer and mathematician, Kepler also progressed the study of optics, and his Keplerian refracting telescope directly builds on Galileo’s own design.

As such an important foundation to our current body of scientific and especially astronomical knowledge, it is great to see that NASA’s new planet finding telescope has been named after him. Equipped with a 95-megapixel array of charge-coupled devices (as used in everyday digital cameras), it has the largest camera ever launched into space. Kepler will orbit the sun in an earth-trailing orbit, looking out towards Cygnus, watching for periodic dimming of stars that would indicate a planet passing in front. It is our best hope so far of finding earth-like planets outside the Solar system.