Observers in the UK with a clear sky at dusk should try to locate Venus low in the western sky an hour after sunset. The 3-day-old slim crescent Moon acts as a convenient guide, located some 12½ degrees (or half the span of an outstretched hand at arm’s length) to the upper left of the brightest planet. Conspicuous star Aldebaran lies in the same low-power binocular field of view as the Moon too. Note that the size of the lunar crescent has been enlarged for clarity. AN graphic by Ade Ashford.Observers in Western Europe should make the most of fine weather to locate Venus low in the western sky an hour after sunset, particularly on Wednesday 18 April when the 3-day-old slim crescent Moon acts as a convenient guide, located some 12½ degrees (or half the span of an outstretched hand at arm’s length) to the upper left of the brightest planet.
Stargazers in the British Isles with a clear sky around 10pm this evening should note the Pleiades (Seven Sisters) forming a right-angled triangle with Venus and the Moon in the deepening twilight, but don’t leave it much later as the brightest planet sets around 10:43pm as seen from the heart of the UK (stated times are in BST).
Prominent first-magnitude star Aldebaran lies in the same low-power binocular field of view as the Moon too. In the small hours of 19 April, the waxing lunar crescent actually occults (passes in front of) Aldebaran as seen from central and northern Russia, north and eastern Scandinavia, the north of Greenland and northernmost Canada.
When a nearby astronomical body passes between the observer and a more distant object, see say that an occultation is taking place. Since the Moon is our nearest celestial neighbour, it regularly passes in front of planets and stars. Observers in the British Isles can see naked-eye star Zeta (ζ) Tauri glide behind the Moon on Saturday, 19 October 2019.
The young crescent Moon’s nightly motion from 31 December 2016 to 3 January 2017 carries it past dazzling planet Venus and first-magnitude Mars. A small telescope also reveals outermost planet Neptune, which passes just 0.02 degrees from Mars around 7h UT on 1 January, offering observers around the world a New Year’s Day treat.
Set your alarm for 6am GMT if you wish to see three naked-eye planets in the UK dawn sky this week. Find a location that offers an unobstructed view of the horizon from southeast to south and let the waning Moon be your guide to locating Jupiter, Mars and Saturn on successive mornings from 7 to 11 February.