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.
Life is hard for a little moon. Epimetheus, seen here with Saturn in the background, is lumpy and misshapen, thanks in part to its size and formation process.
By combining the powerful radar transmitter of the Arecibo Observatory and the Green Bank Telescope (GBT) — the world’s largest fully steerable radio telescope — astronomers were able to penetrate the visually opaque atmospheric veil of Venus to make remarkably detailed images of the surface of the planet without leaving Earth.
In the pre-dawn twilight of Tuesday, 1 March, the 21-day-old waning gibbous Moon acts as a convenient celestial guide to planets Saturn and Mars. For observers in the centre of the British Isles, the best time to see this triple conjunction is shortly before 6am GMT, when the trio are highest in the sky to the south.
