Despite the glow of a waxing Moon, early April is a good time to catch a glimpse of comets 41P/Tuttle–Giacobini–Kresák and C/2015 V2 (Johnson) that are currently circumpolar and visible throughout the UK hours of darkness. And if you’re an early riser, there’s seventh-magnitude C/2017 E4 (Lovejoy) low in the pre-dawn eastern sky too!
Comet 41P/Tuttle–Giacobini–Kresák orbits the Sun every 5.4 years and will pass through perihelion (its closest point to the Sun) on 12 April 2017. Motoring through Ursa Major at close to 2°/day during the remainder of March, this fascinating comet with a history of dramatic surges in brightness, passes close to Messier 97 and 108 on the UK night of 22 March.
Amateur and professional astronomers are invited to provide observations of comets 41P/Tuttle-Giacobini-Kresák, 45P/Honda-Mrkos-Pajdušáková, and 46P/Wirtanen that will pass by Earth at distances ranging from 0.08 to 0.15 astronomical units. Such close approaches of a trio of comets within the next two years are rare and typically occur only once every few decades.