Look to the southern sky at dusk on 12 January to see the 6-day-old waxing crescent Moon just 6½ degrees below magnitude +0.6 Mars in the constellation of Pisces. If you own wide-angle 7× or 8× binoculars, you can see the pair in the same field of view. Note that the Moon’s apparent size has been enlarged for clarity in this illustration. AN graphic by Ade Ashford.Observers in the British Isles and Western Europe looking up at the waxing lunar crescent around nautical dusk (some 1½ hours after sunset in the UK) on Saturday, 12 January will notice that the Moon is not alone – an orange-coloured magnitude +0.6 ‘star’ lies less than a span of a fist at arm’s length above it. This bright interloper in the otherwise modest stars of the constellation of Pisces is none other than Mars.
Some 24 weeks after its close opposition of 2018, the Red Planet presently lies almost 204 million kilometres from Earth, hence its tiny gibbous disc spans just 6.9 arcseconds. Not surprisingly, little in the way of martian surface detail will be evident except in large backyard instruments.
Our Moon has half the physical diameter of Mars, but the Red Planet appears so much smaller since it lies more than 500 times farther away this night. In fact, you need a telescope magnifying in excess of 260× to enlarge Mars to the same apparent size as the adjacent Moon appears to the unaided eye on 12 January.
Currently unmistakable as a brilliant ‘evening star’ over to west at dusk, planet Venus treks through the constellation of Taurus starting April 7th, leading to a close encounter with the Pleiades star cluster on the 11th.
Observers in Western Europe 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 on 18 April. Prominent star Aldebaran lies in the same low-power binocular field of view as the Moon too.
