- Planétarium Rio Tinto Alcan
From December 4 to 18, 2017
Mercury becomes fainter and is now too close to the Sun: the tiny planet is presently unobservable. Mercury passes between Earth and the Sun (inferior conjunction) on December 12, following which it rapidly emerges in the morning sky for a favourable apparition that begins on December 21.
Venus is ending its stint as the Morning Star: the bright planet is drawing closer to the Sun and vanishes in the glow of approaching sunrise. You may still be able to spot it with binoculars, very low in the east-southeast 20 minutes before sunrise — but we’ll lose sight of it definitely during the second week of December. Venus passes behind the Sun (superior conjunction) on January 9, and will reappear in the evening sky later that month.
Mars is slowly pulling away from the sun’s glare and now rises more than 4 hours before our star. You’ll find Mars in the southeast at the end of the night and at dawn. The lunar crescent will hang less than 5 degrees from Mars on the morning of December 13. Notice how bright Jupiter is drawing closer and closer to Mars over the coming weeks.
Jupiter is pulling away from the Sun and rapidly gains height in the morning sky: the bright planet rises about 3 hours before the Sun, and shines at dawn in the southeast. The lunar crescent will hang less than 4 degrees from Jupiter on the morning of December 14. Notice how bright Jupiter is drawing closer and closer to Mars (to its upper right) over the coming weeks.
Saturn is now too close to the southwest horizon at sunset, and vanishes in the Sun’s glare. The Ringed Planet passes behind the Sun (conjunction) on December 21, and gradually reappears at dawn during the first week of January.