The moon is at last quarter as April begins. A few days later, on the 6th, Venus is less than a degree away, an occultation in the eastern hemisphere. The moon is new on the 7th, as well as being at perigee, resulting in large tides. It won't affect prairie dwellers, but Nova Scotians are in for an extreme tide on April 9. That same day, the minor planet Vesta is just a fraction of a degree away, another occultation in the western Pacific region. On the 10th, the bright star in Taurus, Aldebaran, is occulted for observers in the USA and southern Canada. By the 18th, Jupiter has a close approach of only two degrees away. The full phase is reached on April 21, at apogee, resulting in the smallest full moon of 2016. On Monday, April 25, the moon, Saturn, Mars and Antares form a tight group early in the morning eastern sky.
Mercury puts on its best show this year for observers in Canada, shining all month long in the western evening sky at sundown. On the 8th, the very thin crescent of the moon will be a tough observation right at the horizon at sunset.
Venus is bright in the dawn eastern sky, right at sunrise, but by month-end is rounding in its orbit behind the sun. Watch for the moon close by on the 6th.
Mars rises in the late evening, remaining visible all through the night. Earth in its faster orbit overtakes the Red Planet and thus Mars begins retrograde motion on the 17th, appearing to move westward against the starry background.
Jupiter is in the southeast at sunset, well placed for springtime viewing. It also is retrograding in the constellation Leo. Watch for the moon nearby on the 18th.
Saturn is retrograding, too, in the constellation Ophiuchus. It rises in late evening, crossing the sky until dawn's light obliterates the ringed planet.
Uranus is behind the sun, appearing in the dawn sky late in the month.
Neptune is a tough challenge for northern viewers, as it appears in the eastern sky at dawn.
James Edgar has had an interest in the night sky all his life. He joined The Royal Astronomical Society of Canada in 2000 and is now the society's president, editor of the renowned Observer's Handbook, and production manager of the bi-monthly RASC Journal. He was given the RASC Service Award at the 2012 General Assembly in Edmonton.
