As April 2020 opens, dazzling Venus at dusk is drawing ever closer to the magnificent Pleiades (Seven Sisters) in the constellation of Taurus. The brightest planet makes its closest approach to this famous open star cluster on the UK night of 3 April, when typical 10×50 binoculars and small telescopes will deliver memorable views around 9pm BST.
Dazzling planet Venus continues to be a useful celestial signpost to other planets at dusk. Having already showcased Neptune and Mercury this year, the brightest planet has a close conjunction with Uranus on the UK evening of Sunday, 8 March. The pair lie just 2.2 degrees apart against the constellation backdrop of Aries, simultaneously visible in typical 10×50 binoculars.
For three evenings from 26–28 February 2020, observers in Western Europe including the British Isles can watch the waxing crescent Moon’s changing configuration with brightest planet Venus in the west-southwest at dusk. The pair are closest for UK-based observers on the evening of Thursday, 27 February, simultaneously visible in low-power binoculars.
Mercury is poised to put on a fine evening show for Northern Hemisphere observers at dusk, attaining a greatest elongation 18.2 degrees east of the Sun on Monday, 10 February 2020. For ten evenings starting 3 February, the innermost planet and its brightest sibling, Venus, maintain an almost constant angular separation low in the west-southwest 40 minutes after UK sunset.
Even casual skywatchers cannot fail to notice brightest planet Venus currently hanging like a lantern above the southwest horizon at dusk. But as Venus moves eastwards through Aquarius on successive nights, it draws closer to outermost (and faintest) planet Neptune until the pair reach a particularly close conjunction on the UK evening of Monday, 27 January.
Mercury attains a very favourable western elongation of almost 28 degrees from the Sun on 11 April, which means that the innermost planet is a morning object in the eastern sky before sunrise. Antipodean skywatchers are in the enviable position of being able to see Mercury and Venus close together for several mornings in a dark sky before the onset of astronomical twilight.
On Saturday, 2 March 2019, observers in Western Europe should seek a location offering a level and unobstructed southeastern view at civil dawn (some 36 minutes before sunrise in the heart of the UK) to have a chance of seeing the 25-day-old waning crescent Moon between Venus in Capricornus and Saturn in Sagittarius with the unaided eye.