Let’s hope for some clear skies on the morning of 21 August, so we can observe the beautiful ringed planet Saturn being occulted by the Moon. Both Saturn’s disappearance and reappearance can be observed from the UK, as Saturn, being just a few weeks away from opposition, is well placed in the morning sky, located between 25° and 20° high in the south-west.
Saturn is occulted at the bright northern limb of a 97.5 per cent-illuminated waning gibbous Moon at 4.28am BST from London (4.33am in Edinburgh). The Moon’s strong glare doesn’t help, though a pair of binoculars and, particularly, a small telescope will show easily enough Saturn disappearing behind the lunar limb over the course of a minute or so.
Titan, lying close to one of its maximum westerly elongations this month, precedes Saturn’s occultation by a minute or so. It also pops back into view first, reappearing at the limb of the Moon’s thin, unlit portion at around 5.13am (4.58am in Edinburgh), with Saturn following on at around 5.20am (5.09am in Edinburgh).
From London, Saturn reappears at that part of the Moon’s limb adjacent to Mare Crisium, the dark, circular ‘Sea of Crises’. In a high-power telescopic view it’ll be fascinating to watch as Saturn rings begin to come back into view. From Edinburgh though, Saturn reappears 22° further north along the dark limb.
