Mercury

Best time to see: 21 Dec, one hour before sunrise Altitude: 6º (low) Location: Ophiuchus Direction: Southeast

Mercury is in a good position in the morning this month. A 4%-lit waning crescent Moon sits 7.5° west of mag. +0.8 Mercury on 5 December. A telescope will show an 8 arc-second, 23%-lit crescent on this date. Both phase and brightness increase as the planet moves towards greatest eastern elongation (21°) on 15 December when mag. –0.2 Mercury rises two hours before the Sun. On 21 December mag. –0.4 Mercury passes 1° from mag. –1.6 Jupiter, a situation repeated the following morning. At the end of the month mag. –1.6 Mercury rises above the southeast horizon about one hour before the Sun.