Escape to the country

It comes as a great surprise when you encounter dark skies away from light pollution, especially in summer and autumn when the Milky Way straddles and dominates the sky. Its twists and tears amaze the eye and dark areas around Cygnus abound. It can be quite confusing to spot constellations with the naked eye: gone is the W of Cassiopeia, to be replaced by a square-tailed kite! With binoculars and scopes, the deep sky opens up. Galaxies once elusive from town become bright with signs of structure and dust lanes, and those many clusters open out in brightness against a black curtain. So get far away from light pollution, enjoy a pristine sky: it’s really worth the effort! It gives us a great sense of what ancient civilisations saw and puzzled over. Nicholas Cox, Swadlincote, Derbyshire hypothetical Sun-Jupiter system does indeed lie just outside the Sun, this does not apply in a planetary system with a veritable ‘zoo’ of other objects. The Solar System actually has a common barycentre influenced by the Sun, the planets, comets, asteroids and even nearby stars. Its barycentre changes position on quite a grand scale, moving in loops and spirals over many decades, influenced notably by conjunctions of the gas giants. Sometimes the barycentre is within the Sun and sometimes outside – the maximum distance it can be from the Sun’s surface is periodically as much as a solar radius. The effect of Jupiter on its own, while substantial, is somewhat lost in the ‘noise’ of all the other gravitational interactions. Jon Watson, Astronomical Society of Edinburgh

Thanks for the inspiring words, Nicholas. No further persuasion needed! – Ed A valuable insight, Jon. The context of the Jupiter-Sun relationship is indeed important.