As nautical twilight starts at 7am GMT for the centre of the British Isles on 9 January, planets Venus and Saturn are separated by just 9¼ arcminutes — less than a third of the apparent diameter of the full Moon — very low to the southeast. They were at their closest (5 arcminutes) at 4am GMT, but below the UK horizon at that time. Both planets lie 6⅔ degrees to the upper left of star Antares, so all three will fit within the field of view of a 7×50 binocular. AN graphic by Ade Ashford.On Saturday, 9 January at 3:57am GMT, magnitude -4.0 Venus passes just 5 arcminutes — less than one tenth of a degree — north of magnitude +0.5 Saturn. While the instant of closest approach will be missed by observers in the extreme west of Europe as Venus and Saturn will still be below the horizon, by 7am GMT the ‘double-planet’ will be high enough to be glimpsed with the naked eye very low to the southeast from the UK.
By 7am GMT the gap between these two prominent planets will have widened to 9¼ arcminutes — still less than a third of the apparent diameter of the full Moon. Observers with motorised equatorial or GoTo mounts can track the rising pair in the same eyepiece field at magnifications up to 175x until Saturn fades into daylight.
As always, whenever observing in daylight please take extreme care lest the Sun enters the field of view of your telescope or finder with disastrous consequences for your eyesight or anyone else who accidentally looks at it.
On the morning of Thursday, 7 January, observers in the UK with a clear sky and an unobstructed view low to the southeast at 7am GMT (central British Isles) can see a close conjunction between the old crescent Moon, Venus and Saturn — all three encompassed by the field of view of a typical binocular.
Many of you may have tracked down an asteroid with binoculars or a telescope, but have you ever seen one with the naked eye? If not, then June presents you with an opportunity to see the brightest, 4 Vesta, at a close opposition. What’s more, ringed planet Saturn lies close by to act as a convenient guide.
The first ten days of May offer observers in the British Isles their best opportunity to see Mercury in the early evening twilight during 2015. So, if you’ve never seen the innermost planet, let dazzling Venus be your convenient guide to this elusive little world.
