Galileo’s Jupiter

I often wonder how much more in-touch people were long ago with other people and especially with nature.  We know so much more now, but are often so fixated on our own agendas and mortal stuff that I can’t help feeling we’ve lost a large part of our sense of place and belonging.

Jupiter is bright in the evening sky at the moment and has been for a while – it’s one of the first “stars” that we see piercing the blue as the evening sets in.  It’s about as bright as Venus and a little further to the east.

Over four hundred years ago, in 1610, Galileo turned his newly invented telescope toward Jupiter and discovered what we have since called the four Galilean moons – Io, Ganymede, Europa, and Callisto.  He first thought they were fixed stars, but soon discovered that they were actually orbiting Jupiter.  I’m sure that the average person back then was much more in touch with the night sky than today, so many people would have known where Jupiter was in the sky and that it was not a normal star at all, but a planet (from Greek – “wandering star”) even though they didn’t really know what the actual difference was between a star and a planet.

Many people today have binoculars, but few have used them to repeat Galileo’s discovery for themselves, even though binoculars are all you need.  It gives me such delight to share my enthusiasm and watch someone who for the first time looks at Jupiter through binoculars or a telescope and finds that it’s not a star at all, but appears as a little disc with at least three of its moons clearly visible.  If you’ve never done it for yourself, there’s never been a better time.  You will need to steady your binoculars by resting your hand against a wall or something stable.  If you find you need to verify that the little pin-pricks of light around Jupiter are really his moons, you can download one of the many a free astronomy programs that will show you their current positions (I use Cartes du Ceil: http://www.ap-i.net/skychart/en/download).  If you’re at all like me, on seeing this for the first time you will come away feeling somehow profoundly grounded and with an increased sense of wonder about the cosmos and this special place within it that we call home.