August opens with the moon a waning gibbous object, near last quarter, and best viewed after midnight. It will cross the sky all morning, setting at noon.
Full moon occurs Aug. 24, the smallest full moon of the year, as it is furthest from us in its elliptical orbit. Aug. 7, it is among the stars of cluster M35; Aug. 13, Mercury shares the spotlight, along with Venus, Mars, and Saturn, all grouped together on the western horizon; by Aug. 17, the moon and Antares are within two degrees of each other; and Aug. 26, Jupiter is within seven degrees.
Mercury comes into view in the west after sunset. Pick a location with a clear view of the horizon, and perhaps binoculars to see the fleet planet. The best nights will be Aug. 1 to 12. Look for the thin sliver of the moon below Mercury Aug. 11 and below the cluster of planets, Venus, Saturn, and Mars Aug. 12.
Venus is near the greatest extent eastward in its orbit, while first Saturn, and then Mars, pass by on the evenings of Aug. 7 and 19, respectively. Even though the two planets appear to pass Venus, it is the Earth moving in its orbit that causes the illusion - Saturn and Mars continue to move eastward against the starry backdrop, while Venus is seemingly stationary. If proof was necessary, watch the bright double star, Spica, over successive evenings, as it closes in on the planetary trio. Spica isn't moving westward - it's the Solar System moving eastward that gives motion to the stars.
Mars, mentioned a couple of times already, is in a tight triangular grouping with Venus and Saturn for the entire month, giving a perfect opportunity to see the clock of the Solar System ticking away. Mars and Saturn are within two degrees of each other Aug. 1, and Saturn gradually pulls away throughout the month. Aug. 24, Venus and Mars are in a similar conjunction.
Jupiter rises late in the evening, crossing the sky all through the night. Watch for the moon just north of the giant planet on Aug. 26.
Uranus hovers near Jupiter all month long, rising slightly before around 11 p.m. Binoculars will be a helpful aid to view the greenish blue disk of this gas giant. Interestingly, Uranus is tipped nearly on its side, so that its south pole points off toward the west, and its moons orbit in a near-vertical orientation. Something hit Uranus very hard during the early days of the Solar System.
Neptune rises around 9:30 p.m., and crosses the sky all night. A small telescope is likely necessary to see this gas planet - it's 30 times farther from the sun than we are.
Aug. 12 is the peak night for the Perseid meteor shower. No instruments are necessary; just set up a cozy lawn chair and a blanket with a view to the north, get a mug of hot chocolate and lie back to watch the show. You can potentially see 200 meteors per hour as Earth rushes through the dust left behind from an early pass of Comet Swift-Tuttle, discovered in 1862.
- James Edgar has had an interest in the night sky all his life. He joined The Royal Astronomical Society of Canada in 2000 and quickly became involved in the Society. He is edito's Assistant and a contributor to Observer's Handbook, production manager of the bi-monthly RASC Journal, and is the society's national secretary.