The moon is full as the month begins, ending in full phase again - two full moons in one month. Aug.11, the moon occults (passes in front of) Jupiter for viewers in the western Pacific; it's a close conjunction for others.
Two days later, Venus is occulted for most of North America. These are early morning events with a thin waning moon. Just before sunrise, the morning of Aug.16 sees Mercury in the east beside a very thin moon. Mars, Saturn and Spica share the sky with our satellite Aug.21, an evening close grouping in the southwestern sky.
Mercury makes an appearance in the early dawn sky before mid-month, getting brighter with each passing day. Watch for the nearby moon Aug.16.
Venus is in the eastern morning sky all month, with the interloping moon covering the bright planet Aug.13. The occultation event occurs in mid-afternoon, so is hidden from view, except perhaps for telescope users.
Mars lies low in the western evening sky, moving eastward daily to catch and pass between Saturn and Spica Aug.13. Then, the moon catches all three by Aug. 21. "Curiosity" is the Mars rover, otherwise known as the Mars Science Laboratory, that is destined to land on the evening of Aug. 5. It has been travelling since Nov. 26. If all goes well, the rover will spend 23 months or more analyzing Martian rocks and soil. See http://marsprogram.jpl.nasa.gov/msl/.
Jupiter is visible in the morning sky in Taurus, the Bull. Aug.11, the moon joins the scene, covering the giant Jupiter for viewers in the South Pacific. This should offer a great photographic opportunity, as the Pleiades and Hyades clusters hover nearby.
Saturn is low in the western sky at sunset. The ringed planet doesn't appear to move quickly, so it shows up close to the bright double star, Spica, all through the month.
Uranus rises in late evening, crossing the sky all night.
Neptune likewise crosses the sky throughout the darkness, leading Uranus by about an hour. Its great distance requires a telescope in order to be seen - it is four light-hours away, and a mere speck!
The evening of Aug. 11 and early morning of Aug. 12 bring the Perseid meteor shower. Watch for upwards of 90 meteors per hour under good viewing conditions, as Earth passes through the debris left behind from previous passages of Comet Swift-Tuttle.
- James Edgar has had an interest in the night sky all his life. He joined The Royal Astronomical Society of Canada in 2000. He is editor's assistant and a contributor to Observer's Handbook, production manager of the bi-monthly RASC Journal, and is the society's national secretary. He was given the RASC Service Award at the 2012 General Assembly in Edmonton.
