A spectacular grouping of Mercury, Venus and Jupiter graces late May's evening sky, with all three visible in the field-of-view of binoculars until the end of May.

Mercury, Venus and Jupiter put on a great display in the evening sky in late May. This is the view from London on the evening of 25 May about 45 minutes after sunset. Image made using the Sky version 5. See larger version.
 
Venus is by far the brightest of the three, blazing away at magnitude -3.9 and will be the celestial signpost for the event. On the evening of 24 May the Sun sets at 9pm BST from London and 9.30pm from Edinburgh. Sweeping the west-north-west horizon with binoculars once you are sure the Sun is below the horizon should snare Venus, with Mercury just over a degree higher than Venus with Jupiter nearly two degrees higher but to Venus' east.

Fleet-footed Mercury has just emerged into the evening sky following superior conjunction and pulls ever-east of the Sun on its way to greatest elongation on 12 June. This is quite a favourable evening apparition for us the UK but the seemingly never-ending, lingering and lengthening twilight will make it tougher to see. Mercury shines at mag. -0.94 and shows a 81 percent phase across its 5.7 arcsecond disc. Jupiter is at the end of its period of visibility, having a date with solar conjunction in mid-June. However it's still a splendid sight shining just short of mag. -2 and showing an impressive 32 arcsecond disc if you can get a small telescope on it.

Over the next few days the trio converge as Mercury pulls further clear of the horizon, Venus following suit at a more sedate pace and Jupiter sinks slightly further into the mire; on the evening of the 27th Mercury is 2.5 degrees north of Jupiter and Venus passes within a degree north on the 28th. Mercury fades to mag. -0.34 by the month’s end as its apparent diameter increases to 6.4 arcseconds and phase decreases to 63.2 percent. Venus has a ten-arcsecond illuminated by 95 percent. The conjunction of Venus and Jupiter will be a spectacular telescopic sight despite the low altitude.

Mercury continues to be visible as an evening star through to mid-June but it will be an increasingly difficult object as it fades and sinks back into the mire close to the evening horizon. Observers in the Southern Hemisphere and the tropics should have an easier time of it and the innermost planet will be close to Venus again around 20-21 June.

Astronomy Now would be delighted to receive any images of this exciting conjunction; please send them to gallery2013@astronomynow.com.