The Night Sky This Month

Northern HemisphereIan Morison tells us what we can see in the northern hemisphere night sky during January 2018. Jupiter. Jupiter is now a pre-dawn object rising some three and a half hours before the Sun at the beginning of the month with its 33 arc second disk, shining at a magnitude of -1.8, to be seen under clear skies. As the month progresses, its apparent diameter increases to 35.8 arc seconds and it brightens to magnitude -2. The elevation before dawn will then be sufficiently high to enable crisp views of the giant planet to be seen with the equatorial bands, sometimes the Great (but reducing in size) Red Spot and up to four of its Galilean moons visible in a small telescope. Saturn. Saturn passed behind the Sun on December 21st (superior conjunction) on December 21st and reappears in the pre dawn sky this month at the start of its new apparition. It is unlikely to be seen in the first week of January, but climbs higher and so becomes easier to spot as the month progresses as its brightnes