On the UK night of 6—7 July 2017, three weeks after the opposition of Saturn in the constellation of Ophiuchus, the ringed planet can be identified as the magnitude-zero ‘star’ highest in the southern UK sky around 11:40pm BST. As seen from the heart of the British Isles at this time, Saturn struggles to attain a peak altitude of just 14 degrees, or three-quarters of the span of an outstretched hand held at arm’s length above the horizon.
While there is a slim chance that you can confuse Saturn with first-magnitude Antares in the constellation of Scorpius that lies 14 degrees (or one-and-a-half spans of a fist held at arm’s length) to the right of the planet, the supergiant star is the fainter of the two and has a reddish-orange hue in binoculars and small telescopes.Returning to Saturn in a small telescope, the UK night of 6—7 July is ideal for spotting the ringed planet’s largest moon, Titan. This cloud-covered world some 3,200 miles in diameter looks just like a magnitude +9 star close to its greatest westerly elongation from Saturn, some 4½ ring diameters away. Titan orbits its parent planet every 16 days, so expect to see it a similar distance to the east of Saturn on 14 July.
For reasons not yet understood, Saturn seems to store energy in its atmosphere over decades before suddenly releasing it in massive lightning storms that affect the ringed planet’s atmosphere across enormous distances. The Great Northern Storm of 2010/11 circled Saturn like a snake eating its tail, persisting for months before dissipating.
Observers in the UK with clear skies on the night of 30—31 December 2017 can see the 12-day-old waxing gibbous Moon glide through the Hyades cluster in Taurus, occulting a number of naked-eye stars along the way, culminating in the disappearance and reappearance of first-magnitude star Aldebaran in the small hours of New Year’s Eve.
Dominating this image is the so-called Prawn Nebula, part of the gigantic nebula Gum 56, some 6,000 light-years away in Scorpius. For millions of years stars have been born out of the nebula’s gas, material which is later returned to the stellar nursery when the aging stars either expel their material gently into space, or eject it more dramatically in supernova explosions.