With the added challenge of poor weather predictions for the UK this evening, hopefully some fortunate observer(s) will have an opportunity to see a young crescent Moon just 28 hours old.
If you see a window of clear sky an hour after sunset you’ll have to be quick, as the Moon will be very low in the southwest, so you’ll need a pair of binoculars and a flat, unobscured horizon. Let bright Venus be your guide and move two binocular fields (just over 7°) to the right to find the whisker-thin 2% lunar crescent. If you succeed in viewing the Moon, low power binoculars (7×50, 7×35, etc.) will have Mercury in the same field.
As the inclination of the ecliptic to the western horizon steepens over the spring months for Northern Hemisphere observers, opportunities to see the young crescent Moon for longer after sunset generally improve over the next few lunations. But for the next few months at least, January 21st offers your best bet at seeing a really young Moon from the British Isles — weather permitting, of course…
20th February at 6:15 pm — Venus close to Mars in conjunction with a 2-day-old Moon.
21st March at 7:15 pm — Mars in conjunction with a 1.6-day-old Moon.
19th April at 9:00 pm — Mars, Mercury and 1.2-day-old Moon (Moon’s altitude ~3°).