From Nigel Henbest
Thanks for a great article by Colin Stuart (15 March, p 38) on habitable planets. I keep telling people the idea of the habitable zone is outdated, and this feature sums it up brilliantly. But I was a bit perturbed that it kicks off with a couple of historical mistakes.
Galileo was never tried for “heresy”, rather for teaching the Copernican theory – muddling the two is a bit like confusing a conviction for speeding with one for causing death by dangerous driving. And Galileo’s telescope was not good enough to show “moons crossing the face of Jupiter”; he observed the moons alternately to the left and right of the planet, and concluded they were orbiting.
Loosley Row, Buckinghamshire, UK
