My dear Galileo,

Each evening for weeks now I have carried my telescope to the top of a nearby hill and pointed its 70mm objective lens toward the clearly visible bright dot in the sky that I have learned to identify as Jupiter. Bringing it into focus, its 17.5x magnification – more than your early 8x model but less than your eventual 20x one – shows me clearly that what I am seeing is not a star but a planet; a planet with tiny illuminated dots seemingly nearby it.